All Outputs (334)

Launching the VASCO Citizen Science Project (2022)
Journal Article
Villarroel, B., Pelckmans, K., Solano, E., Laaksoharju, M., Souza, A., Dom, O. N., …Ward, M. J. (2022). Launching the VASCO Citizen Science Project. Universe, 8(11), Article 561. https://doi.org/10.3390/universe8110561

The Vanishing & Appearing Sources during a Century of Observations (VASCO) project investigates astronomical surveys spanning a time interval of 70 years, searching for unusual and exotic transients. We present herein the VASCO Citizen Science Projec... Read More about Launching the VASCO Citizen Science Project.

A high angular resolution view of the PAH emission in Seyfert galaxies using JWST/MRS data (2022)
Journal Article
García-Bernete, I., Rigopoulou, D., Alonso-Herrero, A., Donnan, F., Roche, P., Pereira-Santaella, M., …Packham, C. (2022). A high angular resolution view of the PAH emission in Seyfert galaxies using JWST/MRS data. Astronomy & Astrophysics, 666, Article L5. https://doi.org/10.1051/0004-6361/202244806

Polycyclic aromatic hydrocarbons (PAHs) are carbon-based molecules that are ubiquitous in a variety of astrophysical objects and environments. In this work we use JWST/MIRI MRS spectroscopy of three Seyferts to compare their nuclear PAH emission with... Read More about A high angular resolution view of the PAH emission in Seyfert galaxies using JWST/MRS data.

Detection of an unidentified soft X-ray emission feature in NGC 5548 (2022)
Journal Article
Gu, L., Mao, J., Kaastra, J. S., Mehdipour, M., Pinto, C., Grafton-Waters, S., …Ward, M. (2022). Detection of an unidentified soft X-ray emission feature in NGC 5548. Astronomy & Astrophysics, 665, Article A93. https://doi.org/10.1051/0004-6361/202244075

Context. NGC 5548 is an X-ray bright Seyfert 1 active galaxy. It exhibits a variety of spectroscopic features in the soft X-ray band, in particular including the absorption by the active galactic nucleus (AGN) outflows of a broad range of ionization... Read More about Detection of an unidentified soft X-ray emission feature in NGC 5548.

Multiple locations of near-infrared coronal lines in NGC 5548 (2022)
Journal Article
Kynoch, D., Landt, H., Dehghanian, M., Ward, M. J., & Ferland, G. J. (2022). Multiple locations of near-infrared coronal lines in NGC 5548. Monthly Notices of the Royal Astronomical Society, 516(3), https://doi.org/10.1093/mnras/stac2443

We present the first intensive study of the variability of the near-infrared coronal lines in an active galactic nucleus (AGN). We use data from a 1-yr-long spectroscopic monitoring campaign with roughly weekly cadence on NGC 5548 to study the variab... Read More about Multiple locations of near-infrared coronal lines in NGC 5548.

Multiwavelength campaign on the Super-Eddington NLS1 RX J0134.2-4258 – I. Peculiar X-ray spectra and variability (2022)
Journal Article
Jin, C., Done, C., Ward, M., Panessa, F., Liu, B., & Liu, H. (2022). Multiwavelength campaign on the Super-Eddington NLS1 RX J0134.2-4258 – I. Peculiar X-ray spectra and variability. Monthly Notices of the Royal Astronomical Society, 512(4), 5642-5656. https://doi.org/10.1093/mnras/stac827

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.

A glint in the eye: Photographic plate archive searches for non-terrestrial artefacts (2022)
Journal Article
Villarroel, B., Mattsson, L., Guergouri, H., Solano, E., Geier, S., Dom, O. N., & Ward, M. J. (2022). A glint in the eye: Photographic plate archive searches for non-terrestrial artefacts. Acta Astronautica, 194, 106-113. https://doi.org/10.1016/j.actaastro.2022.01.039

In this paper, we present a simple strategy to identify Non-Terrestrial artefacts [NTAs; Haqq-Misra and Kopparapu (2012)] in or near geosynchronous Earth orbits (GEOs). We show that even the small pieces of reflective debris in orbit around the Earth... Read More about A glint in the eye: Photographic plate archive searches for non-terrestrial artefacts.

X-ray intraday variability and power spectral density profiles of the blazar 3C 273 with XMM–Newton during 2000–2021 (2022)
Journal Article
Pavana Gowtami, G., Gaur, H., Gupta, A. C., Wiita, P. J., Liao, M., & Ward, M. (2022). X-ray intraday variability and power spectral density profiles of the blazar 3C 273 with XMM–Newton during 2000–2021. Monthly Notices of the Royal Astronomical Society, 511(2), 3101-3112. https://doi.org/10.1093/mnras/stac286

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
Baldi, R., Williams, D., Beswick, R., McHardy, I., Dullo, B., Knapen, J., …Ward, M. (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. Monthly Notices of the Royal Astronomical Society, 508(2), 2019-2038. https://doi.org/10.1093/mnras/stab2613

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
Zhao, X., Civano, F., Fornasini, F., Alexander, D., Cappelluti, N., Chen, C., …Windhorst, R. (2021). The NuSTAR extragalactic survey of the James Webb Space Telescope North Ecliptic Pole time-domain field. Monthly Notices of the Royal Astronomical Society, 508(4), 5176-5195. https://doi.org/10.1093/mnras/stab2885

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
Trindade Falcão, A., Kraemer, S., Fischer, T., Crenshaw, D., Revalski, M., Schmitt, H., …Ward, M. (2021). Hubble Space Telescope [O iii] emission-line kinematics in two nearby QSO2s: a case for X-ray feedback. Monthly Notices of the Royal Astronomical Society, 505(2), 3054-3069. https://doi.org/10.1093/mnras/stab1549

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.

On the multiwavelength variability of Mrk 110: two components acting at different time-scales (2021)
Journal Article
Vincentelli, F., McHardy, I., Cackett, E., Barth, A., Horne, K., Goad, M., …Williams, D. (2021). On the multiwavelength variability of Mrk 110: two components acting at different time-scales. Monthly Notices of the Royal Astronomical Society, 504(3), 4337-4353. https://doi.org/10.1093/mnras/stab1033

We present the first intensive continuum reverberation mapping study of the high accretion-rate Seyfert galaxy Mrk 110. The source was monitored almost daily for more than 200 d with the Swift X-ray and ultraviolet (UV)/optical telescopes, supported... Read More about On the multiwavelength variability of Mrk 110: two components acting at different time-scales.

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
Jin, C., Done, C., & Ward, M. (2021). 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. Monthly Notices of the Royal Astronomical Society, 500(2), 2475-2495. https://doi.org/10.1093/mnras/staa3386

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.

Broad He i 1.08-µm absorption from the obscurer in the active galaxy NGC 5548 (2020)
Journal Article
Wildy, C., Landt, H., Ward, M. J., Czerny, B., & Kynoch, D. (2021). Broad He i 1.08-µm absorption from the obscurer in the active galaxy NGC 5548. Monthly Notices of the Royal Astronomical Society: Letters, 500(2), 2063-2075. https://doi.org/10.1093/mnras/staa3301

The nucleus of the active galaxy NGC 5548 was the target of two intensive spectroscopic monitoring campaigns at X-ray, ultraviolet (UV), and optical frequencies in 2013/2014. These campaigns detected the presence of a massive obscuration event. In 20... Read More about Broad He i 1.08-µm absorption from the obscurer in the active galaxy NGC 5548.

Geometry of the X-ray source 1H 0707–495 (2020)
Journal Article
Szanecki, M., Niedźwiecki, A., Done, C., Klepczarek, Ł., Lubiński, P., & Mizumoto, M. (2020). Geometry of the X-ray source 1H 0707–495. Astronomy & Astrophysics, 641, Article A89. https://doi.org/10.1051/0004-6361/202038303

Aims. We investigate the constraints on the size and location of the X-ray source in 1H 0707–495 determined from the shape of the relativistically smeared reflection from the accretion disc. Methods. We developed a new code to model an extended X-ray... Read More about Geometry of the X-ray source 1H 0707–495.

Reobserving the NLS1 galaxy RE J1034+396 – I. The long-term, recurrent X-ray QPO with a high significance (2020)
Journal Article
Ward, M., Done, C., & Jin, C. (2020). Reobserving the NLS1 galaxy RE J1034+396 – I. The long-term, recurrent X-ray QPO with a high significance. Monthly Notices of the Royal Astronomical Society, 495(4), 3538-3550. https://doi.org/10.1093/mnras/staa1356

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.

State-of-the-art AGN SEDs for Photoionization Models: BLR Predictions Confront the Observations (2020)
Journal Article
Ward, M. J., Landt, H., Jin, C., Done, C., & Ferland, G. J. (2020). State-of-the-art AGN SEDs for Photoionization Models: BLR Predictions Confront the Observations. Monthly Notices of the Royal Astronomical Society, 494(4), 5917-5922. https://doi.org/10.1093/mnras/staa1207

The great power offered by photoionization models of Active Galactic Nuclei (AGN) emission line regions has long been mitigated by the fact that very little is known about the spectral energy distribution (SED) between the Lyman limit, where interven... Read More about State-of-the-art AGN SEDs for Photoionization Models: BLR Predictions Confront the Observations.

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
Villarroel, B., Soodla, J., Comerón, S., Mattsson, L., Pelckmans, K., López-Corredoira, M., …Ward, M. J. (2020). 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”. Astronomical Journal, 159(1), Article 8. https://doi.org/10.3847/1538-3881/ab570f

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
Landt, H., Ward, M. J., Kynoch, D., Packham, C., Ferland, G. J., Lawrence, A., …Winkler, H. (2019). The first spectroscopic dust reverberation programme on active galactic nuclei: the torus in NGC 5548. Monthly Notices of the Royal Astronomical Society, 489(2), 1572-1589. https://doi.org/10.1093/mnras/stz2212

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.

The relativistic jet of the γ-ray emitting narrow-line Seyfert 1 galaxy PKS J1222+0413 (2019)
Journal Article
Kynoch, D., Landt, H., Ward, M. J., Done, C., Boisson, C., Baloković, M., Angelakis, E., & Myserlis, I. (2019). The relativistic jet of the γ-ray emitting narrow-line Seyfert 1 galaxy PKS J1222+0413. Monthly Notices of the Royal Astronomical Society, 487(1), 181-197. https://doi.org/10.1093/mnras/stz1193

We present a multi-frequency study of PKS J1222+0413 (4C +04.42), currently the highest redshift γ-ray emitting narrow-line Seyfert 1 (γ-NLS1). We assemble a broad spectral energy distribution (SED) including previously unpublished datasets: X-ray da... Read More about The relativistic jet of the γ-ray emitting narrow-line Seyfert 1 galaxy PKS J1222+0413.

Torus model properties of an ultra-hard X-ray selected sample of Seyfert galaxies (2019)
Journal Article
García-Bernete, I., Ramos Almeida, C., Alonso-Herrero, A., Ward, M., Acosta-Pulido, J., Pereira-Santaella, M., …Fuller, L. (2019). Torus model properties of an ultra-hard X-ray selected sample of Seyfert galaxies. Monthly Notices of the Royal Astronomical Society, 486(4), 4917-4935. https://doi.org/10.1093/mnras/stz1003

We characterize for the first time the torus properties of an ultra-hard X-ray (14–195 keV) volume-limited (DL < 40 Mpc) sample of 24 Seyfert (Sy) galaxies (BCS40 sample). The sample was selected from the Swift/BAT nine-month catalogue.We use high an... Read More about Torus model properties of an ultra-hard X-ray selected sample of Seyfert galaxies.