Skip to main content

Research Repository

Advanced Search

Outputs (331)

TREASUREHUNT: Transients and Variability Discovered with HST in the JWST North Ecliptic Pole Time-domain Field (2024)
Journal Article
O’Brien, R., Jansen, R. A., Grogin, N. A., Cohen, S. H., Smith, B. M., Silver, R. M., …Acharya, T. (2024). TREASUREHUNT: Transients and Variability Discovered with HST in the JWST North Ecliptic Pole Time-domain Field. Astrophysical Journal Supplement, 272(1), Article 19. https://doi.org/10.3847/1538-4365/ad3948

The James Webb Space Telescope (JWST) North Ecliptic Pole (NEP) Time-domain Field (TDF) is a >14′ diameter field optimized for multiwavelength time-domain science with JWST. It has been observed across the electromagnetic spectrum both from the groun... Read More about TREASUREHUNT: Transients and Variability Discovered with HST in the JWST North Ecliptic Pole Time-domain Field.

The first spectroscopic IR reverberation programme on Mrk 509 (2024)
Journal Article
Mitchell, J. A. J., Ward, M. J., Kynoch, D., Santisteban, J. V. H., Horne, K., Pott, J. .-U., …Winkler, H. (2024). The first spectroscopic IR reverberation programme on Mrk 509. Monthly Notices of the Royal Astronomical Society, 529(4), 4824-4839. https://doi.org/10.1093/mnras/stae790

Near IR spectroscopic reverberation of Active Galactic Nuclei (AGN) potentially allows the infrared (IR) broad line region (BLR) to be reverberated alongside the disc and dust continua, while the spectra can also reveal details of dust astro-chemistr... Read More about The first spectroscopic IR reverberation programme on Mrk 509.

AGN STORM 2. V. Anomalous Behavior of the C iv Light Curve of Mrk 817 (2024)
Journal Article
Homayouni, Y., Kriss, G. A., De Rosa, G., Plesha, R., Cackett, E. M., Goad, M. R., …Zu, Y. (2024). AGN STORM 2. V. Anomalous Behavior of the C iv Light Curve of Mrk 817. Astrophysical Journal, 963(2), Article 123. https://doi.org/10.3847/1538-4357/ad1be4

An intensive reverberation mapping campaign of the Seyfert 1 galaxy Mrk 817 using the Cosmic Origins Spectrograph on the Hubble Space Telescope revealed significant variations in the response of broad UV emission lines to fluctuations in the continuu... Read More about AGN STORM 2. V. Anomalous Behavior of the C iv Light Curve of Mrk 817.

Deconvolution of JWST/MIRI Images: Applications to an Active Galactic Nucleus Model and GATOS Observations of NGC 5728 (2024)
Journal Article
Leist, M. T., Packham, C., Rosario, D. J. V., Hope, D. A., Alonso-Herrero, A., Hicks, E. K. S., …Shimizu, T. (2024). Deconvolution of JWST/MIRI Images: Applications to an Active Galactic Nucleus Model and GATOS Observations of NGC 5728. Astronomical Journal, 167(3), Article 96. https://doi.org/10.3847/1538-3881/ad1886

The superb image quality, stability, and sensitivity of JWST permit deconvolution techniques to be pursued with a fidelity unavailable to ground-based observations. We present an assessment of several deconvolution approaches to improve image quality... Read More about Deconvolution of JWST/MIRI Images: Applications to an Active Galactic Nucleus Model and GATOS Observations of NGC 5728.

The Galaxy Activity, Torus, and Outflow Survey (GATOS): III. Revealing the inner icy structure in local active galactic nuclei (2023)
Journal Article
García-Bernete, I., Alonso-Herrero, A., Rigopoulou, D., Pereira-Santaella, M., Shimizu, T., Davies, R., …Ward, M. J. (2024). The Galaxy Activity, Torus, and Outflow Survey (GATOS): III. Revealing the inner icy structure in local active galactic nuclei. Astronomy & Astrophysics, 681, Article L7. https://doi.org/10.1051/0004-6361/202348266

We use JWST/MIRI MRS spectroscopy of a sample of six local obscured type 1.9/2 active galactic nuclei (AGN) to compare their nuclear mid-IR absorption bands with the level of nuclear obscuration traced by X-rays. This study is the first to use subarc... Read More about The Galaxy Activity, Torus, and Outflow Survey (GATOS): III. Revealing the inner icy structure in local active galactic nuclei.

Breakthrough results in astrobiology: is ‘high risk’ research needed? (2023)
Journal Article
Jeancolas, C., Gillen, C., McMahon, S., Ward, M., & Vickers, P. J. (2023). Breakthrough results in astrobiology: is ‘high risk’ research needed?. International Journal of Astrobiology, https://doi.org/10.1017/s1473550423000241

Astrobiology is a scientific endeavour involving great uncertainties. This could justify intellectual risk-taking associated with research that significantly deviates from the mainstream, to explore new avenues. However, little is known regarding the... Read More about Breakthrough results in astrobiology: is ‘high risk’ research needed?.

Wavelength dependences of the optical/UV and X-ray luminosity correlations of quasars (2023)
Journal Article
Ward, M., Done, C., Jin, C., Lusso, E., & Middei, R. (2024). Wavelength dependences of the optical/UV and X-ray luminosity correlations of quasars. Monthly Notices of the Royal Astronomical Society, 527(1), 356–373. https://doi.org/10.1093/mnras/stad3193

The interband correlations between optical/ultraviolet (UV) and X-ray luminosities of active galactic nuclei (AGNs) are important for understanding the disc–coronal connection, as well as using AGN as standard candles for cosmology. It is convention... Read More about Wavelength dependences of the optical/UV and X-ray luminosity correlations of quasars.

Delayed appearance and evolution of coronal lines in the TDE AT2019qiz (2023)
Journal Article
Short, P., Lawrence, A., Nicholl, M., Ward, M., Reynolds, T. M., Mattila, S., …Wevers, T. (2023). Delayed appearance and evolution of coronal lines in the TDE AT2019qiz. Monthly Notices of the Royal Astronomical Society, 525(1), 1568-1587. https://doi.org/10.1093/mnras/stad2270

Tidal disruption events (TDEs) occur when a star gets torn apart by a supermassive black hole as it crosses its tidal radius. We present late-time optical and X-ray observations of the nuclear transient AT2019qiz, which showed the typical signs of an... Read More about Delayed appearance and evolution of coronal lines in the TDE AT2019qiz.

MIDIS: Strong (Hβ+[O iii]) and Hα Emitters at Redshift z ≃ 7–8 Unveiled with JWST NIRCam and MIRI Imaging in the Hubble eXtreme Deep Field (2023)
Journal Article
Rinaldi, P., Caputi, K. I., Costantin, L., Gillman, S., Iani, E., Pérez-González, P. G., …Kokorev, V. (2023). MIDIS: Strong (Hβ+[O iii]) and Hα Emitters at Redshift z ≃ 7–8 Unveiled with JWST NIRCam and MIRI Imaging in the Hubble eXtreme Deep Field. Astrophysical Journal, 952(2), Article 143. https://doi.org/10.3847/1538-4357/acdc27

We make use of JWST medium-band and broadband NIRCam imaging, along with ultradeep MIRI 5.6 μm imaging, in the Hubble eXtreme Deep Field to identify prominent line emitters at z ≃ 7–8. Out of a total of 58 galaxies at z ≃ 7–8, we find 18 robust candi... Read More about MIDIS: Strong (Hβ+[O iii]) and Hα Emitters at Redshift z ≃ 7–8 Unveiled with JWST NIRCam and MIRI Imaging in the Hubble eXtreme Deep Field.

Life beyond 30: Probing the −20 < M UV < −17 Luminosity Function at 8 < z < 13 with the NIRCam Parallel Field of the MIRI Deep Survey (2023)
Journal Article
Pérez-González, P. G., Costantin, L., Langeroodi, D., Rinaldi, P., Annunziatella, M., Ilbert, O., …María Mérida, R. (2023). Life beyond 30: Probing the −20 < M UV < −17 Luminosity Function at 8 < z < 13 with the NIRCam Parallel Field of the MIRI Deep Survey. Astrophysical Journal Letters, 951:L1(1), 1-14. https://doi.org/10.3847/2041-8213/acd9d0

We present the ultraviolet luminosity function and an estimate of the cosmic star formation rate density at 8 < z < 13 derived from deep NIRCam observations taken in parallel with the MIRI Deep Survey of the Hubble Ultra Deep Field (HUDF), NIRCam cov... Read More about Life beyond 30: Probing the −20 < M UV < −17 Luminosity Function at 8 < z < 13 with the NIRCam Parallel Field of the MIRI Deep Survey.

The SOUX AGN sample: optical/UV/X-ray SEDs and the nature of the disc (2023)
Journal Article
Mitchell, J. A. J., Done, C., Ward, M. J., Kynoch, D., Hagen, S., Lusso, E., & Landt, H. (2023). The SOUX AGN sample: optical/UV/X-ray SEDs and the nature of the disc. Monthly Notices of the Royal Astronomical Society, 524(2), 1796-1825. https://doi.org/10.1093/mnras/stad1830

We use the SOUX sample of ∼700 active galactic nucleus (AGN) to form average optical-ultraviolet (UV)-X-rays spectral energy distributions (SEDs) on a two-dimensional (2D) grid of MBH and L2500. We compare these with the predictions of a new AGN SED... Read More about The SOUX AGN sample: optical/UV/X-ray SEDs and the nature of the disc.

AGN STORM 2. II. Ultraviolet Observations of Mrk 817 with the Cosmic Origins Spectrograph on the Hubble Space Telescope* (2023)
Journal Article

We present reverberation mapping measurements for the prominent ultraviolet broad emission lines of the active galactic nucleus Mrk 817 using 165 spectra obtained with the Cosmic Origins Spectrograph on the Hubble Space Telescope. Our ultraviolet obs... Read More about AGN STORM 2. II. Ultraviolet Observations of Mrk 817 with the Cosmic Origins Spectrograph on the Hubble Space Telescope*.

The SOUX AGN sample: SDSS–XMM-Newton optical, ultraviolet, and X-ray selected active galactic nuclei spanning a wide range of parameter space – sample definition (2023)
Journal Article
Kynoch, D., Mitchell, J. A. J., Ward, M. J., Done, C., Lusso, E., & Landt, H. (2023). The SOUX AGN sample: SDSS–XMM-Newton optical, ultraviolet, and X-ray selected active galactic nuclei spanning a wide range of parameter space – sample definition. Monthly Notices of the Royal Astronomical Society, 520(2), 2781-2805. https://doi.org/10.1093/mnras/stad221

We assemble a sample of 696 type 1 active galactic nuclei (AGN) up to a redshift of z = 2.5, all of which have an SDSS spectrum containing at least one broad emission line (H α, H β, or Mg II) and an XMM-Newton X-ray spectrum containing at least 250... Read More about The SOUX AGN sample: SDSS–XMM-Newton optical, ultraviolet, and X-ray selected active galactic nuclei spanning a wide range of parameter space – sample definition.

The long-term broad-line responsivity in MKN 110 (2022)
Journal Article
Homan, D., Lawrence, A., Ward, M., Bruce, A., Landt, H., MacLeod, C., …Peterson, B. M. (2023). The long-term broad-line responsivity in MKN 110. Monthly Notices of the Royal Astronomical Society, 519(2), 1745-1763. https://doi.org/10.1093/mnras/stac3571

We examine the long-term history of the optical spectrum of the extremely variable Active Galactic Nucleus (AGN) MKN 110. By combining various archival data with new data, we cover an unprecedented long period of ∼30 yr (1987–2019). We find that the... Read More about The long-term broad-line responsivity in MKN 110.

Torus and polar dust dependence on active galactic nucleus properties (2022)
Journal Article
García-Bernete, I., González-Martín, O., Ramos Almeida, C., Alonso-Herrero, A., Martínez-Paredes, M., Ward, M. J., …Esparza-Arredondo, D. (2022). Torus and polar dust dependence on active galactic nucleus properties. Astronomy & Astrophysics, 667, 1-43. https://doi.org/10.1051/0004-6361/202244230

We present a statistical analysis of the properties of the obscuring material around active galactic nuclei (AGN). This study represents the first of its kind for an ultra-hard X-ray (14–195 keV; Swift/BAT), volume-limited (DL <  40 Mpc) sample of 24... Read More about Torus and polar dust dependence on active galactic nucleus properties.

Multiwavelength campaign on the Super-Eddington NLS1 RX J0134.2-4258 – I. Peculiar X-ray spectra and variability (2022)
Journal Article

We have conducted a new long-term multiwavelength campaign on one of the most super-Eddington narrow-line Seyfert 1s (NLS1s) known, namely RX J0134.2-4258. In this first paper, we report deep simultaneous X-ray observations performed by XMM–Newton an... Read More about Multiwavelength campaign on the Super-Eddington NLS1 RX J0134.2-4258 – I. Peculiar X-ray spectra and variability.

X-ray intraday variability and power spectral density profiles of the blazar 3C 273 with XMM–Newton during 2000–2021 (2022)
Journal Article

We present X-ray intraday variability and power spectral density (PSD) analyses of the longest 23 pointed XMM–Newton observations of the blazar 3C 273 that were taken during 2000–2021. These good time intervals contain between 5 and 24.6 h of data. V... Read More about X-ray intraday variability and power spectral density profiles of the blazar 3C 273 with XMM–Newton during 2000–2021.

LeMMINGs III. The e-MERLIN legacy survey of the Palomar sample: exploring the origin of nuclear radio emission in active and inactive galaxies through the [O iii] – radio connection (2021)
Journal Article

What determines the nuclear radio emission in local galaxies? To address this question, we combine optical [O III] line emission, robust black hole (BH) mass estimates, and high-resolution e-MERLIN 1.5-GHz data, from the LeMMINGs survey, of a statist... Read More about LeMMINGs III. The e-MERLIN legacy survey of the Palomar sample: exploring the origin of nuclear radio emission in active and inactive galaxies through the [O iii] – radio connection.

The NuSTAR extragalactic survey of the James Webb Space Telescope North Ecliptic Pole time-domain field (2021)
Journal Article

We present the NuSTAR extragalactic survey of the James Webb Space Telescope (JWST) North Ecliptic Pole (NEP) Time-Domain Field. The survey covers a ∼0.16 deg2 area with a total exposure of 681 ks acquired in a total of nine observations from three e... Read More about The NuSTAR extragalactic survey of the James Webb Space Telescope North Ecliptic Pole time-domain field.

Hubble Space Telescope [O iii] emission-line kinematics in two nearby QSO2s: a case for X-ray feedback (2021)
Journal Article

We present a dynamical study of the narrow-line regions in two nearby type 2 quasars (QSO2s). We construct dynamical models based on detailed photoionization models of the emission-line gas, including the effects of internal dust, to apply to observa... Read More about Hubble Space Telescope [O iii] emission-line kinematics in two nearby QSO2s: a case for X-ray feedback.

Re-observing the NLS1 galaxy RE J1034+396 – II. New insights on the soft X-ray excess, QPO, and the analogy with GRS 1915+105 (2020)
Journal Article

The active galactic nucleus (AGN) RE J1034+396 displays the most significant X-ray quasi-periodic oscillation (QPO) detected so far. We perform a detailed spectral-timing analysis of our recent simultaneous XMM–Newton, NuSTAR, and Swift observations.... Read More about Re-observing the NLS1 galaxy RE J1034+396 – II. New insights on the soft X-ray excess, QPO, and the analogy with GRS 1915+105.

Reobserving the NLS1 galaxy RE J1034+396 – I. The long-term, recurrent X-ray QPO with a high significance (2020)
Journal Article

RE J1034+396 is a narrow-line Seyfert 1 galaxy (NLS1) in which the first significant X-ray quasi-periodic oscillation (QPO) in an active galactic nucleus (AGN) was observed in 2007. We report the detection of this QPO in a recent XMM–Newton observati... Read More about Reobserving the NLS1 galaxy RE J1034+396 – I. The long-term, recurrent X-ray QPO with a high significance.

The Vanishing and Appearing Sources during a Century of Observations Project. I. USNO Objects Missing in Modern Sky Surveys and Follow-up Observations of a “Missing Star” (2020)
Journal Article

In this paper we report the current status of a new research program. The primary goal of the "Vanishing and Appearing Sources during a Century of Observations" project is to search for vanishing and appearing sources using existing survey data to fi... Read More about The Vanishing and Appearing Sources during a Century of Observations Project. I. USNO Objects Missing in Modern Sky Surveys and Follow-up Observations of a “Missing Star”.

The first spectroscopic dust reverberation programme on active galactic nuclei: the torus in NGC 5548 (2019)
Journal Article

We have recently initiated the first spectroscopic dust reverberation programme on active galactic nuclei in the near-infrared. Spectroscopy enables measurement of dust properties, such as flux, temperature, and covering factor, with higher precision... Read More about The first spectroscopic dust reverberation programme on active galactic nuclei: the torus in NGC 5548.

Hubble Space Telescope Observations of Extended [O iii]λ 5007 Emission in Nearby QSO2s: New Constraints on AGN Host Galaxy Interaction (2018)
Journal Article

We present a Hubble Space Telescope survey of extended [O iii] λ5007 emission for a sample of 12 nearby (z < 0.12), luminous Type 2 quasars (QSO2s), which we use to measure the extent and kinematics of their AGN-ionized gas. We find that the size of... Read More about Hubble Space Telescope Observations of Extended [O iii]λ 5007 Emission in Nearby QSO2s: New Constraints on AGN Host Galaxy Interaction.

Super-Eddington QSO RX J0439.6-5311 – II. Multiwavelength constraints on the global structure of the accretion flow (2017)
Journal Article

We present a detailed multiwavelength study of an unobscured, highly super-Eddington Type-1 QSO RX J0439.6-5311. We combine the latest XMM–Newton observation with all archival data from infrared to hard X-rays. The optical spectrum is very similar to... Read More about Super-Eddington QSO RX J0439.6-5311 – II. Multiwavelength constraints on the global structure of the accretion flow.

Reaching the peak of the quasar spectral energy distribution – II. Exploring the accretion disc, dusty torus and host galaxy (2016)
Journal Article

We continue our study of the spectral energy distributions (SEDs) of 11 active galactic nuclei (AGN) at 1.5 < z < 2.2, with optical–near-infrared (NIR) spectra, X-ray data and mid-IR photometry. In a previous paper, we presented the observations and... Read More about Reaching the peak of the quasar spectral energy distribution – II. Exploring the accretion disc, dusty torus and host galaxy.

Discovery of very high energy γ-ray emission from the BL Lacertae object PKS 0301−243 with H.E.S.S (2013)
Journal Article

The active galactic nucleus PKS 0301−243 (z = 0.266) is a high-synchrotron-peaked BL Lac object that is detected at high energies (HE, 100 MeV 100 GeV) by the High Energy Stereoscopic System (H.E.S.S.) from observations between September 2009 and De... Read More about Discovery of very high energy γ-ray emission from the BL Lacertae object PKS 0301−243 with H.E.S.S.

Constraints on axionlike particles with H.E.S.S. from the irregularity of the PKS 2155-304 energy spectrum (2013)
Journal Article

Axionlike particles (ALPs) are hypothetical light (sub-eV) bosons predicted in some extensions of the Standard Model of particle physics. In astrophysical environments comprising high-energy gamma rays and turbulent magnetic fields, the existence of... Read More about Constraints on axionlike particles with H.E.S.S. from the irregularity of the PKS 2155-304 energy spectrum.

Discovery of TeV γ-ray emission from PKS 0447-439 and derivation of an upper limit on its redshift (2013)
Journal Article

Very high-energy γ-ray emission from PKS 0447−439 was detected with the H.E.S.S. Cherenkov telescope array in December 2009. This blazar is one of the brightest extragalactic objects in the Fermi bright source list and has a hard spectrum in the MeV... Read More about Discovery of TeV γ-ray emission from PKS 0447-439 and derivation of an upper limit on its redshift.

H.E.S.S. observations of the binary system PSR B1259-63/LS 2883 around the 2010/2011 periastron passage (2013)
Journal Article

Aims. We present very high energy (VHE; E > 100 GeV) data from the γ-ray binary system PSR B1259-63/LS 2883 taken around its periastron passage on 15th of December 2010 with the High Energy Stereoscopic System (H.E.S.S.) of Cherenkov Telescopes. We a... Read More about H.E.S.S. observations of the binary system PSR B1259-63/LS 2883 around the 2010/2011 periastron passage.

Measurement of the extragalactic background light imprint on the spectra of the brightest blazars observed with H.E.S.S (2013)
Journal Article

The extragalactic background light (EBL) is the diffuse radiation with the second highest energy density in the Universe after the cosmic microwave background. The aim of this study is the measurement of the imprint of the EBL opacity to γ-rays on th... Read More about Measurement of the extragalactic background light imprint on the spectra of the brightest blazars observed with H.E.S.S.

A combined optical and X-ray study of unobscured type 1 active galactic nuclei - I. Optical spectra and spectral energy distribution modelling (2012)
Journal Article

We present modelling and interpretation of the continuum and emission lines for a sample of 51 unobscured type 1 active galactic nuclei (AGNs). All of these AGNs have high-quality spectra from both XMM–Newton and the Sloan Digital Sky Survey. We exte... Read More about A combined optical and X-ray study of unobscured type 1 active galactic nuclei - I. Optical spectra and spectral energy distribution modelling.

Detection of extended very-high-energy gamma-ray emission towards the young stellar cluster Westerlund 2 (2007)
Journal Article

Aims. Results from $\gamma$-ray observations by the HESS telescope array in the direction of the young stellar cluster Westerlund 2 are presented. Methods. Stereoscopic imaging of Cherenkov light emission of $\gamma$-ray induced showers in the atmosp... Read More about Detection of extended very-high-energy gamma-ray emission towards the young stellar cluster Westerlund 2.

Constraints on accretion in ultraluminous X-ray sources from Spitzer IRS observations of NGC 4485/4490: Infrared diagnostic diagrams (2007)
Journal Article

Constraining the astrophysical nature of ultraluminous X-ray (ULX) sources, which have X-ray luminosities exceeding 1039 ergs s1, has been elusive due to the optical faintness of any counterparts. With high spectral resolution observations in the ∼10... Read More about Constraints on accretion in ultraluminous X-ray sources from Spitzer IRS observations of NGC 4485/4490: Infrared diagnostic diagrams.

Discovery of very high energy γ-ray emission from the BL Lacertae object H 2356-309 with the HESS Cherenkov telescopes (2006)
Journal Article

The extreme synchrotron BL Lac object H 2356-309, located at a redshift of z = 0.165, was observed from June to December 2004 with a total exposure of $\approx$40 h live-time with the HESS (High Energy Stereoscopic System) array of atmospheric-Cheren... Read More about Discovery of very high energy γ-ray emission from the BL Lacertae object H 2356-309 with the HESS Cherenkov telescopes.

First detection of a VHE gamma-ray spectral maximum from a cosmicsource: HESS discovery of the Vela X nebula (2006)
Journal Article
Aharonian, F., Akhperjanian, A., Bazer-Bachi, A., Beilicke, M., Benbow, W., Berge, D., …Ward, M. (2006). First detection of a VHE gamma-ray spectral maximum from a cosmicsource: HESS discovery of the Vela X nebula. Astronomy & Astrophysics, 448(2), L43-L47. https://doi.org/10.1051/0004-6361%3A200600014

The Vela supernova remnant (SNR) is a complex region containing a number of sources of non-thermal radiation. The inner section of this SNR, within 2 degrees of the pulsar PSR B0833-45 , has been observed by the HESS $\gamma$-ray atmospheric Cherenko... Read More about First detection of a VHE gamma-ray spectral maximum from a cosmicsource: HESS discovery of the Vela X nebula.

An XMM-Newton view of M101 - II. Global X-ray source properties. (2005)
Journal Article
Jenkins, L., Roberts, T., Warwick, R., Kilgard, R., & Ward, M. (2005). An XMM-Newton view of M101 - II. Global X-ray source properties. Monthly Notices of the Royal Astronomical Society, 357(2), 401-419. https://doi.org/10.1111/j.1365-2966.2005.08645.x

We present the global X-ray properties of the point source population in the grand-design spiral galaxy M101, as seen with XMM–Newton. 108 X-ray sources are detected within the D25 ellipse of M101, of which ∼24 are estimated to be background galaxies... Read More about An XMM-Newton view of M101 - II. Global X-ray source properties..

A new description of the X-ray spectra of ULXs (2004)
Journal Article
Roberts, T., Warwick, R., Stobbart, A., Goad, M., Ward, M., Kilgard, R., & Jenkins, L. (2004). A new description of the X-ray spectra of ULXs. Bulletin of the American Astronomical Society, 8,

An XMM-Newton view of the luminous X-ray source population of M101. (2004)
Journal Article
Jenkins, L., Roberts, T., Warwick, R., Kilgard, R., & Ward, M. (2004). An XMM-Newton view of the luminous X-ray source population of M101. Memorie Della Società Astronomica Italiana, 75(3),

We present the first results of an XMM n EPIC observation of the luminous X-ray source population in the face-on supergiant spiral galaxy M101. We have studied the X-ray spectral and temporal properties of the most luminous sources in M101 at the tim... Read More about An XMM-Newton view of the luminous X-ray source population of M101..

High-resolution imaging of the He II λ4686 emission line nebula associated with the ultraluminous X-ray source in Holmberg II (2004)
Journal Article
Kaaret, P., Ward, M., & Zezas, A. (2004). High-resolution imaging of the He II λ4686 emission line nebula associated with the ultraluminous X-ray source in Holmberg II. Monthly Notices of the Royal Astronomical Society, 351(3), L83-L88. https://doi.org/10.1111/j.1365-2966.2004.08020.x

We present Hubble Space Telescope images of the He iii region surrounding the bright X-ray source in the dwarf irregular galaxy Holmberg II. Using Chandra, we find a position for the X-ray source of (J2000) with an uncertainty of 0.6 arcsec. We ident... Read More about High-resolution imaging of the He II λ4686 emission line nebula associated with the ultraluminous X-ray source in Holmberg II.

An XMM-Newton view of M101 - I. The luminous X-ray source population. (2004)
Journal Article
Jenkins, L., Roberts, T., Warwick, R., Kilgard, R., & Ward, M. (2004). An XMM-Newton view of M101 - I. The luminous X-ray source population. Monthly Notices of the Royal Astronomical Society, 349(2), 404-424. https://doi.org/10.1111/j.1365-2966.2004.07546.x

We present the first results of an XMM–Newton EPIC observation of the luminous X-ray source population in the face-on supergiant spiral galaxy M101. We have studied the spectral and temporal properties of the 14 most luminous sources, all of which ha... Read More about An XMM-Newton view of M101 - I. The luminous X-ray source population..

The Collimated Wind in NGC 253 (2003)
Journal Article
Sugai, H., Davies, R., & Ward, M. (2003). The Collimated Wind in NGC 253. Astrophysical Journal, 584, L9-L12

A massive x-ray outflow from the quasar PDS 456 (2003)
Journal Article
Reeves, J., O'Brien, P., & Ward, M. (2003). A massive x-ray outflow from the quasar PDS 456. Astrophysical Journal Letters, 593(2), L65-L68. https://doi.org/10.1086/378218

We report on XMM-Newton spectroscopic observations of the luminous radio-quiet quasar PDS 456. The hard X-ray spectrum of PDS 456 shows a deep absorption trough (constituting 50% of the continuum) at energies above 7 keV in the quasar rest frame, whi... Read More about A massive x-ray outflow from the quasar PDS 456.

The unusual supernova remnant surrounding the ultraluminous X-ray source IC 342 X-1 (2003)
Journal Article
Roberts, T., Goad, M., Ward, M., & Warwick, R. (2003). The unusual supernova remnant surrounding the ultraluminous X-ray source IC 342 X-1. Monthly Notices of the Royal Astronomical Society, 342(3), 709-714. https://doi.org/10.1046/j.1365-8711.2003.06593.x

We report the results of an observation of a large-diameter (110 pc) supernova remnant (SNR) found to encircle the position of the ultraluminous X-ray source (ULX) IC 342 X-1. The inferred initial energy input to the SNR is at least 2-3 times greater... Read More about The unusual supernova remnant surrounding the ultraluminous X-ray source IC 342 X-1.

A Chandra Survey of Nearby Spiral Galaxies (2002)
Journal Article
Kilgard, R., Krauss, M., Prestwich, A., Kaaret, P., Garcia, M., Zezas, A., …Roberts, T. (2002). A Chandra Survey of Nearby Spiral Galaxies. Bulletin of the American Astronomical Society, 34, 1121-

A Chandra observation of the interacting pair of galaxies NGC 4485/4490 (2002)
Journal Article
Roberts, T., Warwick, R., Ward, M., & Murray, S. (2002). A Chandra observation of the interacting pair of galaxies NGC 4485/4490. Monthly Notices of the Royal Astronomical Society, 337(2), 677-692. https://doi.org/10.1046/j.1365-8711.2002.05950.x

We report the results of a 20-ks Chandra ACIS-S observation of the galaxy pair NGC 4485/4490. This is an interacting system containing a late-type spiral with an enhanced star formation rate (NGC 4490), and an irregular companion that possesses a dis... Read More about A Chandra observation of the interacting pair of galaxies NGC 4485/4490.

Chandra observations of the luminous infrared galaxy NGC 3256 (2002)
Journal Article
Lira, P., Ward, M., Zezas, A., Alonso-Herrero, A., & Ueno, S. (2002). Chandra observations of the luminous infrared galaxy NGC 3256. Monthly Notices of the Royal Astronomical Society, 330(2), 259-278. https://doi.org/10.1046/j.1365-8711.2002.05014.x

We present a detailed analysis of high-resolution Chandra observations of the merger system NGC 3256, the most infrared-luminous galaxy in the nearby universe. The X-ray data show that several discrete sources embedded in complex diffuse emission con... Read More about Chandra observations of the luminous infrared galaxy NGC 3256.

An X-ray/optical study of IXOs (2001)
Journal Article
Roberts, T., Goad, M., Ward, M., Warwick, R., O'Brien, P., Lira, P., & Hands, A. (2001). An X-ray/optical study of IXOs. Bulletin of the American Astronomical Society, 33, 858-

Identifying X-ray Sources in Bulge and Disk Galaxies (2001)
Journal Article
Prestwich, A., Kilgard, R., Krauss, M., Kaaret, P., Zezas, A., McDowell, J., …Trinchieri, G. (2001). Identifying X-ray Sources in Bulge and Disk Galaxies. Bulletin of the American Astronomical Society, 33, 1338-

The identification of an optical counterpart to the super-Eddington X-ray source NGC 5204 X-1 (2001)
Journal Article
Roberts, T., Goad, M., Ward, M., Warwick, R., O'Brien, P., Lira, P., & Hands, A. (2001). The identification of an optical counterpart to the super-Eddington X-ray source NGC 5204 X-1. Monthly Notices of the Royal Astronomical Society, 325(2), L7-L11. https://doi.org/10.1046/j.1365-8711.2001.04659.x

We report the identification of a possible optical counterpart to the super-Eddington X-ray source NGC 5204 X-1. New Chandra data show that the X-ray source is point-like, with a luminosity of 5.2×10^39 erg/s (0.5-8 keV). It displays medium- and long... Read More about The identification of an optical counterpart to the super-Eddington X-ray source NGC 5204 X-1.

Ultraluminous x-ray sources in external galaxies (2001)
Journal Article
King, A., Davies, M., Ward, M., Fabbiano, G., & Elvis, M. (2001). Ultraluminous x-ray sources in external galaxies. Astrophysical Journal Letters, 552(2), L109-L112. https://doi.org/10.1086/320343

We investigate models for the class of ultraluminous nonnuclear X-ray sources (i.e., ultraluminous compact X-ray sources [ULXs]) seen in a number of galaxies and probably associated with star-forming regions. Models in which the X-ray emission is ass... Read More about Ultraluminous x-ray sources in external galaxies.

PDS 456: an extreme accretion rate quasar? (2000)
Journal Article
Reeves, J., O'Brien, P., Vaughan, S., Law-Green, D., Ward, M., Simpson, C., …Edelson, R. (2000). PDS 456: an extreme accretion rate quasar?. Monthly Notices of the Royal Astronomical Society, 312, L17-L21

Fabry-Perot imaging of NGC 6090 in H₂ emission (2000)
Journal Article
Sugai, H., Davies, R., Ishii, M., & Ward, M. (2000). Fabry-Perot imaging of NGC 6090 in H₂ emission. Monthly Notices of the Royal Astronomical Society, 317, 447-452

BeppoSAX observations of luminous IRAS galaxies. (2000)
Journal Article
Ueno, S., Ward, M., O'Brien, P., Stirpe, G., & Matt, G. (2000). BeppoSAX observations of luminous IRAS galaxies. Advances in Space Research, 25(3-4), 823-826. https://doi.org/10.1016/s0273-1177%2899%2900848-0

We have obtained hard X-ray spectra of four luminous IRAS galaxies, which were selected on the basis of their optical polarized broad lines. We have found prominent Fe K line emission from IRAS 20210+1121, suggesting that its observed X-ray continuum... Read More about BeppoSAX observations of luminous IRAS galaxies..

Near- and mid-infrared imaging polarimetry of NGC 1068 (1999)
Journal Article
Lumsden, S., Moore, T., Smith, C., Fujiyoshi, T., Bland-Hawthorn, J., & Ward, M. (1999). Near- and mid-infrared imaging polarimetry of NGC 1068. Monthly Notices of the Royal Astronomical Society, 303, 209-220

The BeppoSAX observation of IRAS 20210+1121 (1999)
Journal Article
Ueno, S., Ward, M., O'Brien, P., Stirpe, G., & Matt, G. (1999). The BeppoSAX observation of IRAS 20210+1121. Nuclear Physics B - Proceedings Supplements, 69(1-3), 554-557. https://doi.org/10.1016/s0920-5632%2898%2900287-4

We have obtained a hard X-ray spectrum of the ultraluminous infrared galaxy IRAS 20210+1121 (z = 0.056), whose optical spectrum is that of a Seyfert 2. The most significant feature is a strong Fe K line at 6.7 (6.5–7.0) keV in the rest-frame with equ... Read More about The BeppoSAX observation of IRAS 20210+1121.

The obscured BLR in the radio galaxy 3C 234 (1998)
Journal Article
Young, S., Hough, J., Axon, D., Fabian, A., & Ward, M. (1998). The obscured BLR in the radio galaxy 3C 234. Monthly Notices of the Royal Astronomical Society, 294, 478-

Excitation of the Extended Gas in NGC 1068 (1997)
Journal Article
Nazarova, L., O'Brien, P., Ward, M., & Gondhalekar, P. (1997). Excitation of the Extended Gas in NGC 1068. Astrophysics and Space Science, 248, 121-126

Optical colour maps of Seyfert galaxies (1997)
Journal Article
Kotilainen, J., & Ward, M. (1997). Optical colour maps of Seyfert galaxies. Astronomy and astrophysics. Supplement series, 121, 77-94

Polarimetry and modelling of narrow-line active galaxies (1996)
Journal Article
Young, S., Hough, J., Efstathiou, A., Wills, B., Bailey, J., Ward, M., & Axon, D. (1996). Polarimetry and modelling of narrow-line active galaxies. Monthly Notices of the Royal Astronomical Society, 281, 1206-1242

The Extended Narrow Line Region in Mkn79 (1996)
Journal Article
Nazarova, L., O'Brien, P., & Ward, M. (1996). The Extended Narrow Line Region in Mkn79. Memorie Della Società Astronomica Italiana, 67, 1005-

Near-infrared and millimetre polarimetry of CEN A (1996)
Journal Article
Packham, C., Hough, J., Young, S., Chrysostomou, A., Bailey, J., Axon, D., & Ward, M. (1996). Near-infrared and millimetre polarimetry of CEN A. Monthly Notices of the Royal Astronomical Society, 278, 406-416

Spatially resolved spectropolarimetry of the galaxy NGC 1068 (1995)
Journal Article
Inglis, M., Young, S., Hough, J., Gledhill, T., Axon, D., Bailey, J., & Ward, M. (1995). Spatially resolved spectropolarimetry of the galaxy NGC 1068. Monthly Notices of the Royal Astronomical Society, 275, 398-416

Imaging the Collimating Structures in Seyfert Galaxies (1995)
Journal Article
Simpson, C., Wilson, A., Ward, M., Alonso-Herrero, A., Mulchaey, ,., & S., J. (1995). Imaging the Collimating Structures in Seyfert Galaxies. Bulletin of the American Astronomical Society, 27, 1321-

The Host Galaxies of SEYFERT-1 Nuclei (1994)
Journal Article
Kotilainen, J., & Ward, M. (1994). The Host Galaxies of SEYFERT-1 Nuclei. Monthly Notices of the Royal Astronomical Society, 266, 953-

The extended narrow line region of NGC 4151 (1994)
Journal Article
Robinson, A., Vila-Vilaro, B., Axon, D., Perez, E., Wagner, S., Baum, S., …Ward, M. (1994). The extended narrow line region of NGC 4151. Astronomy and Astrophysics, 291, 351-391

Infrared Spectroscopy of High-Redshift Quasars (1994)
Journal Article
Baker, A., Carswell, R., Bailey, J., Espey, B., Smith, M., & Ward, M. (1994). Infrared Spectroscopy of High-Redshift Quasars. Monthly Notices of the Royal Astronomical Society, 270, 575-

The U.K. Deep and Medium Surveys with ROSAT - N-Log Relation (1994)
Journal Article
Branduardi Raymont, G., Mason, K., Warwick, R., Carrera, F., Graffagnino, V., Mittaz, J., …Rowan-Robinson, M. (1994). The U.K. Deep and Medium Surveys with ROSAT - N-Log Relation. Monthly Notices of the Royal Astronomical Society, 270, 947-

The obscuration to the nucleus of IC 5063. (1994)
Journal Article
Simpson, C., Ward, M., & Kotilainen, J. (1994). The obscuration to the nucleus of IC 5063. Monthly Notices of the Royal Astronomical Society, 271, 250-256

A ROSAT observation of NGC 5548 (1993)
Journal Article
Nandra, K., Fabian, A., George, I., Branduardi-Raymont, G., Lawrence, A., Mason, K., …Warwick, R. (1993). A ROSAT observation of NGC 5548. Monthly Notices of the Royal Astronomical Society, 260, 504-512

Optical spectroscopy of southern radio galaxies (1993)
Journal Article
Simpson, C., Clements, D., Rawlings, S., & Ward, M. (1993). Optical spectroscopy of southern radio galaxies. Monthly Notices of the Royal Astronomical Society, 262, 889-892

FAST on the WHT. (1991)
Journal Article
Clegg, R., Ward, M., Blietz, M., Cameron, M., Drapatz, S., Genzel, R., …van der Werf, P. (1991). FAST on the WHT

The Buried Quasar in Cygnus A (1991)
Journal Article
Wilson, A., Ward, M., Blanco, P., & Nishida, M. (1991). The Buried Quasar in Cygnus A. Bulletin of the American Astronomical Society, 23, 928-

An optical and near-infrared polarization survey of Seyfert and broad-line radio galaxies. I - Statistical properties. II - The wavelength dependence of polarization (1990)
Journal Article
Brindle, C., Hough, J., Bailey, J., Axon, D., Ward, M., Sparks, W., & McLean, I. (1990). An optical and near-infrared polarization survey of Seyfert and broad-line radio galaxies. I - Statistical properties. II - The wavelength dependence of polarization. Monthly Notices of the Royal Astronomical Society, 244, 577-618

Simultaneous multifrequency observations of the Seyfert 1 galaxy NGC 4051 - Constant optical-infrared emission observed during large-amplitude X-ray variability (1990)
Journal Article
Done, C., Ward, M., Fabian, A., Kunieda, H., Tsuruta, S., Lawrence, A., …Wamsteker, W. (1990). Simultaneous multifrequency observations of the Seyfert 1 galaxy NGC 4051 - Constant optical-infrared emission observed during large-amplitude X-ray variability. Monthly Notices of the Royal Astronomical Society, 243, 713-720

The jets of 3C120 (1989)
Journal Article
Axon, D. J., Pedlar, A., Unger, S., Meurs, E., Whittle, ,., & M., D. (1989). The jets of 3C120. Nature, 341, 631-633

The polarization of NGC 1068 (1988)
Journal Article
Bailey, J., Axon, D., Hough, J., Ward, M., McLean, I., & Heathcote, S. (1988). The polarization of NGC 1068. Monthly Notices of the Royal Astronomical Society, 234, 899-917

A tale of two Seyferts (1987)
Journal Article
Ward, M. (1987). A tale of two Seyferts. Observatory, 107, 268-269

The Deep X-ray Survey in Pavo: Optical Identifications (1986)
Journal Article
Griffiths, R., Brissenden, R., Hewitt, P., Murray, S., Tuohy, I., & Ward, M. (1986). The Deep X-ray Survey in Pavo: Optical Identifications. Bulletin of the American Astronomical Society, 18, 1046-

The 0.3 to 100 Micron Continua of Type 1 Seyferts (1985)
Journal Article
Ward, M., Elvis, M., Fabbiano, G., Carleton, N., Willner, S., & Lawrence, A. (1985). The 0.3 to 100 Micron Continua of Type 1 Seyferts. Bulletin of the American Astronomical Society, 17, 869-

EXOSAT observations of a strong soft X-ray excess in MKN 841 (1985)
Journal Article
Arnaud, K., Branduardi-Raymont, G., Culhane, J., Fabian, A., Hazard, C., McGlynn, T., …J., M. (1985). EXOSAT observations of a strong soft X-ray excess in MKN 841. Monthly Notices of the Royal Astronomical Society, 217, 105-113

JHKL photometry of the nuclei of normal spiral galaxies (1984)
Journal Article
Willner, S., Fabbiano, G., Elvis, M., Ward, M., Longmore, A., & Lawrence, A. (1984). JHKL photometry of the nuclei of normal spiral galaxies. Publications of the Astronomical Society of the Pacific, 96, 143-147

The Velocity Field in the Active Galaxy NGC 7582 (1984)
Journal Article
Morris, S., Ward, M., Whittle, M., Wilson, A., & Taylor, K. (1984). The Velocity Field in the Active Galaxy NGC 7582. Bulletin of the American Astronomical Society, 16, 916-

The Fe(9+) region in active galactic nuclei (1984)
Journal Article
Penston, M., Fosbury, R., Boksenberg, A., Ward, M., & Wilson, A. (1984). The Fe(9+) region in active galactic nuclei. Monthly Notices of the Royal Astronomical Society, 208, 347-364

a 0729+103 (1982)
Journal Article
McHardy, I., Pye, J., Fairall, A., Warner, B., Allen, S., Cropper, M., & Ward, M. (1982). a 0729+103

The variable infrared source near HH100 (1982)
Journal Article
Axon, D., Allen, D., Bailey, J., Hough, J., Ward, M., & Jameson, R. (1982). The variable infrared source near HH100. Monthly Notices of the Royal Astronomical Society, 200, 239-245

The 1979 outburst of U Scorpii (1981)
Journal Article
Barlow, M., Brodie, J., Brunt, C., Hanes, D., Hill, P., Mayo, S., …Willis, A. (1981). The 1979 outburst of U Scorpii. Monthly Notices of the Royal Astronomical Society, 195, 61-78

X-ray emission from active galaxies (1981)
Journal Article
Hayes, M., Bell Burnell, S., Culhane, J., Barr, P., Sanford, P., Ward, M., & Ives, J. (1981). X-ray emission from active galaxies. Space Science Reviews, 30, 39-45

The eclipsing AM Herculis star 2A 0311-227 (1981)
Journal Article
Allen, D., Wright, A., & Ward, M. (1981). The eclipsing AM Herculis star 2A 0311-227. Monthly Notices of the Royal Astronomical Society, 195, 155-164

Observations and models of H2242-035 (1981)
Journal Article
Hassall, B., Pringle, J., Ward, M., Whelan, J., Mayo, S., Echevarria, J., …Hyland, A. (1981). Observations and models of H2242-035. Monthly Notices of the Royal Astronomical Society, 197, 275-286

The variability of 3C 390.3 (1980)
Journal Article
Barr, P., Pollard, G., Sanford, P., Ives, J., Ward, M., Hine, R., …Lloyd, C. (1980). The variability of 3C 390.3. Monthly Notices of the Royal Astronomical Society, 193, 549-562

2A 0311-227 (1979)
Journal Article
Ward, M., Allen, D., Smith, M., & Wright, A. (1979). 2A 0311-227

Infrared observations of this x-ray emitting, AM Her-like star (IAUC 3326) were made with the Anglo-Australian Telescope by M. J. Ward, Institute of Astronomy, Cambridge; and D. A. Allen, M. G. Smith and A. E. Wright, Anglo-Australian Observatory. Fl... Read More about 2A 0311-227.

Identification of Sources in the 3A Catalogue. (1978)
Journal Article
Lawrence, A., McHardy, I., Elvis, M., Ricketts, M., & Ward, M. (1978). Identification of Sources in the 3A Catalogue. Bulletin of the American Astronomical Society, 10, 500-

Supernova in IC 5201 (1978)
Journal Article
Ward, M., Blades, J., & Griffiths, R. (1978). Supernova in IC 5201

Seyfert galaxies as X-ray sources (1978)
Journal Article
Elvis, M., Maccacaro, T., Wilson, A., Ward, M., Penston, M., Fosbury, R., & Perola, G. (1978). Seyfert galaxies as X-ray sources. Monthly Notices of the Royal Astronomical Society, 183, 129-157

NGC 7213 (1978)
Journal Article
Allen, D., Smith, M., Wright, A., Ward, M., & Wilson, A. (1978). NGC 7213

Spectroscopic observations of the X-ray nova A0620-00 (1977)
Journal Article
Whelan, J., Allen, D., Danziger, I., Fosbury, R., Murdin, P., Penston, M., …Ward, M. (1977). Spectroscopic observations of the X-ray nova A0620-00. Monthly Notices of the Royal Astronomical Society, 180, 657-673

New Active Galaxy Identifications of 2A X-ray Sources. (1977)
Journal Article
Ward, M., Wilson, A., Penston, M., Tritton, K., Elvis, M., & Maccacaro, T. (1977). New Active Galaxy Identifications of 2A X-ray Sources. Bulletin of the American Astronomical Society, 9, 558-

NGC 3783 - A possible X-ray emitting Seyfert galaxy (1976)
Journal Article
Cooke, B., Elvis, M., Ward, M., Fosbury, R., Penston, M., & Maccacaro, T. (1976). NGC 3783 - A possible X-ray emitting Seyfert galaxy. Monthly Notices of the Royal Astronomical Society, 177, 121P-125P