All Outputs (88)

Space Telescope and Optical Reverberation Mapping Project. IX. Velocity–Delay Maps for Broad Emission Lines in NGC 5548 (2021)
Journal Article
Horne, K., Rosa, G. D., Peterson, B., Barth, A., Ely, J., Fausnaugh, M., …Zu, Y. (2021). Space Telescope and Optical Reverberation Mapping Project. IX. Velocity–Delay Maps for Broad Emission Lines in NGC 5548. Astrophysical Journal, 907(2), Article 76. https://doi.org/10.3847/1538-4357/abce60

In this contribution, we achieve the primary goal of the active galactic nucleus (AGN) STORM campaign by recovering velocity–delay maps for the prominent broad emission lines (Lyα, C iv, He ii, and Hβ) in the spectrum of NGC 5548. These are the most... Read More about Space Telescope and Optical Reverberation Mapping Project. IX. Velocity–Delay Maps for Broad Emission Lines in NGC 5548.

The mass of the Milky Way out to 100 kpc using halo stars (2020)
Journal Article
Deason, A. J., Erkal, D., Belokurov, V., Fattahi, A., Gómez, F. A., Grand, R. J., …Zhao, G. (2021). The mass of the Milky Way out to 100 kpc using halo stars. Monthly Notices of the Royal Astronomical Society, 501(4), 5964-5972. https://doi.org/10.1093/mnras/staa3984

We use a distribution function analysis to estimate the mass of the Milky Way (MW) out to 100 kpc using a large sample of halo stars. These stars are compiled from the literature, and the vast majority (⁠∼98 per cent⁠) have 6D phase-space information... Read More about The mass of the Milky Way out to 100 kpc using halo stars.

The twisted dark matter halo of the Milky Way (2020)
Journal Article
Shao, S., Cautun, M., Deason, A., & Frenk, C. S. (2021). The twisted dark matter halo of the Milky Way. Monthly Notices of the Royal Astronomical Society, 504(4), 6033-6048. https://doi.org/10.1093/mnras/staa3883

We analyse systems analogous to the Milky Way (MW) in the EAGLE cosmological hydrodynamics simulation in order to deduce the likely structure of the MW’s dark matter (DM) halo. We identify MW mass haloes in the simulation whose satellite galaxies hav... Read More about The twisted dark matter halo of the Milky Way.

Stellar splashback: the edge of the intracluster light (2020)
Journal Article
Deason, A. J., Oman, K. A., Fattahi, A., Schaller, M., Jauzac, M., Zhang, Y., …Evans, T. A. (2021). Stellar splashback: the edge of the intracluster light. Monthly Notices of the Royal Astronomical Society, 500(3), 4181-4192. https://doi.org/10.1093/mnras/staa3590

We examine the outskirts of galaxy clusters in the C-EAGLE simulations to quantify the ‘edges’ of the stellar and dark matter distribution. The radius of the steepest slope in the dark matter, commonly used as a proxy for the splashback radius, is lo... Read More about Stellar splashback: the edge of the intracluster light.

Space Telescope and Optical Reverberation Mapping Project. XII. Broad-line Region Modeling of NGC 5548 (2020)
Journal Article
Williams, P., Pancoast, A., Treu, T., Brewer, B., Peterson, B., Barth, A., …Zu, Y. (2020). Space Telescope and Optical Reverberation Mapping Project. XII. Broad-line Region Modeling of NGC 5548. Astrophysical Journal, 902(1), Article 74. https://doi.org/10.3847/1538-4357/abbad7

We present geometric and dynamical modeling of the broad line region (BLR) for the multi-wavelength reverberation mapping campaign focused on NGC 5548 in 2014. The data set includes photometric and spectroscopic monitoring in the optical and ultravio... Read More about Space Telescope and Optical Reverberation Mapping Project. XII. Broad-line Region Modeling of NGC 5548.

A tale of two populations: surviving and destroyed dwarf galaxies and the build-up of the Milky Way’s stellar halo (2020)
Journal Article
Fattahi, A., Deason, A. J., Frenk, C. S., Simpson, C. M., Gómez, F. A., Grand, R. J., …Pakmor, R. (2020). A tale of two populations: surviving and destroyed dwarf galaxies and the build-up of the Milky Way’s stellar halo. Monthly Notices of the Royal Astronomical Society, 497(4), 4459-4471. https://doi.org/10.1093/mnras/staa2221

We use magneto-hydrodynamical simulations of Milky Way-mass haloes from the Auriga project to investigate the properties of surviving and destroyed dwarf galaxies that are accreted by these haloes over cosmic time. We show that the combined luminosit... Read More about A tale of two populations: surviving and destroyed dwarf galaxies and the build-up of the Milky Way’s stellar halo.

How Unusual is the Milky Way’s Assembly History? (2020)
Journal Article
Evans, T. A., Fattahi, A., Deason, A. J., & Frenk, C. S. (2020). How Unusual is the Milky Way’s Assembly History?. Monthly Notices of the Royal Astronomical Society, 497(4), 4311-4321. https://doi.org/10.1093/mnras/staa2202

In the ΛCDM model of structure formation galactic haloes build up by accretion of mass and mergers of smaller haloes. The most recent massive merger event experienced by the Milky Way (MW) halo was the accretion of the Large Magellanic Cloud (LMC; wh... Read More about How Unusual is the Milky Way’s Assembly History?.

Quantifying the Stellar Halo's Response to the LMC's Infall with Spherical Harmonics (2020)
Journal Article
Cunningham, E. C., Garavito-Camargo, N., Deason, A. J., Johnston, K. V., Erkal, D., Laporte, C. F., …Sanderson, R. E. (2020). Quantifying the Stellar Halo's Response to the LMC's Infall with Spherical Harmonics. Astrophysical Journal, 898(1), Article 4. https://doi.org/10.3847/1538-4357/ab9b88

The vast majority of the mass in the Milky Way (MW) is in dark matter (DM); we therefore cannot directly observe the MW mass distribution and have to use tracer populations in order to infer properties of the MW DM halo. However, MW halo tracers do n... Read More about Quantifying the Stellar Halo's Response to the LMC's Infall with Spherical Harmonics.

The dual origin of the Galactic thick disc and halo from the gas-rich Gaia-Enceladus-Sausage merger (2020)
Journal Article
Pakmor, R., Marinacci, F., Gómez, F. A., Fragkoudi, F., Fattahi, A., Deason, A. J., …Grand, R. J. (2020). The dual origin of the Galactic thick disc and halo from the gas-rich Gaia-Enceladus-Sausage merger. Monthly Notices of the Royal Astronomical Society, 497(2), 1603-1618. https://doi.org/10.1093/mnras/staa2057

We analyse a set of cosmological magneto-hydrodynamic simulations of the formation of Milky Way-mass galaxies identified to have a prominent radially anisotropic stellar halo component similar to the so-called “Gaia Sausage” found in the Gaia data. W... Read More about The dual origin of the Galactic thick disc and halo from the gas-rich Gaia-Enceladus-Sausage merger.

The orbital phase space of contracted dark matter haloes (2020)
Journal Article
Pakmor, R., Marinacci, F., Grand, R. J., Frenk, C. S., Deason, A. J., Cautun, M., & Callingham, T. M. (2020). The orbital phase space of contracted dark matter haloes. Monthly Notices of the Royal Astronomical Society, 495(1), 12-28. https://doi.org/10.1093/mnras/staa1089

We study the orbital phase space of dark matter (DM) haloes in the AURIGA suite of cosmological hydrodynamics simulations of Milky Way (MW) analogues. We characterize haloes by their spherical action distribution, F(Jr,L)⁠, a function of the specific... Read More about The orbital phase space of contracted dark matter haloes.

The Edge of the Galaxy (2020)
Journal Article
Deason, A. J., Fattahi, A., Frenk, C. S., Grand, R. J., Oman, K. A., Garrison-Kimmel, S., …Navarro, J. F. (2020). The Edge of the Galaxy. Monthly Notices of the Royal Astronomical Society, 496(3), 3929-3942. https://doi.org/10.1093/mnras/staa1711

We use cosmological simulations of isolated Milky Way (MW)-mass galaxies, as well as Local Group (LG) analogues, to define the ‘edge’ – a caustic manifested in a drop in density or radial velocity – of Galactic-sized haloes, both in dark matter and i... Read More about The Edge of the Galaxy.

The little things matter: relating the abundance of ultrafaint satellites to the hosts’ assembly history (2020)
Journal Article
Frenk, C. S., Belokurov, V., Deason, A. J., & Bose, S. (2020). The little things matter: relating the abundance of ultrafaint satellites to the hosts’ assembly history. Monthly Notices of the Royal Astronomical Society, 495(1), 743-757. https://doi.org/10.1093/mnras/staa1199

Ultrafaint dwarf galaxies (M⋆ ≤ 105 M⊙) are relics of an early phase of galaxy formation. They contain some of the oldest and most metal-poor stars in the Universe which likely formed before the epoch of hydrogen reionisation. These galaxies are so f... Read More about The little things matter: relating the abundance of ultrafaint satellites to the hosts’ assembly history.

The Milky Way total mass profile as inferred from Gaia DR2 (2020)
Journal Article
Cautun, M., Benítez-Llambay, A., Deason, A. J., Frenk, C. S., Fattahi, A., Gómez, F. A., …Simpson, C. M. (2020). The Milky Way total mass profile as inferred from Gaia DR2. Monthly Notices of the Royal Astronomical Society, 494(3), 4291-4313. https://doi.org/10.1093/mnras/staa1017

We determine the Milky Way (MW) mass profile inferred from fitting physically motivated models to the Gaia DR2 Galactic rotation curve and other data. Using various hydrodynamical simulations of MW-mass haloes, we show that the presence of baryons in... Read More about The Milky Way total mass profile as inferred from Gaia DR2.

The biggest Splash (2020)
Journal Article
Grand, R. J., Evans, N. W., Deason, A. J., Smith, M. C., Fattahi, A., Sanders, J. L., & Belokurov, V. (2020). The biggest Splash. Monthly Notices of the Royal Astronomical Society, 494(3), 3880-3898. https://doi.org/10.1093/mnras/staa876

Using a large sample of bright nearby stars with accurate Gaia Data Release 2 astrometry and auxiliary spectroscopy we map out the properties of the principle Galactic components such as the “thin” and “thick” discs and the halo. We confirm previous... Read More about The biggest Splash.

The Nature of Ionized Gas in the Milky Way Galactic Fountain (2019)
Journal Article
Werk, J. K., Rubin, K., Bish, H., Prochaska, J., Zheng, Y., O’Meara, J., …Deason, A. (2019). The Nature of Ionized Gas in the Milky Way Galactic Fountain. Astrophysical Journal, 887(1), Article 89. https://doi.org/10.3847/1538-4357/ab54cf

We address the spatial scale, ionization structure, mass, and metal content of gas at the Milky Way disk–halo interface detected as absorption in the foreground of seven closely spaced, high-latitude halo blue horizontal branch stars with heights z =... Read More about The Nature of Ionized Gas in the Milky Way Galactic Fountain.

The total stellar halo mass of the Milky Way (2019)
Journal Article
Deason, A. J., Belokurov, V., & Sanders, J. L. (2019). The total stellar halo mass of the Milky Way. Monthly Notices of the Royal Astronomical Society, 490(3), 3426-3439. https://doi.org/10.1093/mnras/stz2793

We measure the total stellar halo luminosity using red giant branch (RGB) stars selected from Gaia data release 2. Using slices in magnitude, colour, and location on the sky, we decompose RGB stars belonging to the disc and halo by fitting two-dimens... Read More about The total stellar halo mass of the Milky Way.

Simulating cosmological substructure in the solar neighbourhood (2019)
Journal Article
Simpson, C. M., Gargiulo, I., Gómez, F. A., Grand, R. J., Maffione, N., Cooper, A. P., …Pakmor, R. (2019). Simulating cosmological substructure in the solar neighbourhood. Monthly Notices of the Royal Astronomical Society: Letters, 490(1), L32-L37. https://doi.org/10.1093/mnrasl/slz142

We explore the predictive power of cosmological, hydrodynamical simulations for stellar phase-space substructure and velocity correlations with the AURIGA simulations and AURIGAIA mock Gaia catalogues. We show that at the solar circle the AURIGA simu... Read More about Simulating cosmological substructure in the solar neighbourhood.

Galactic Gas Flows from Halo to Disk: Tomography and Kinematics at the Milky Way’s Disk–Halo Interface (2019)
Journal Article
Bish, H. V., Werk, J. K., Prochaska, J. X., Rubin, K. H., Zheng, Y., O’Meara, J. M., & Deason, A. J. (2019). Galactic Gas Flows from Halo to Disk: Tomography and Kinematics at the Milky Way’s Disk–Halo Interface. Astrophysical Journal, 882(2), Article 76. https://doi.org/10.3847/1538-4357/ab3414

We present a novel absorption-line survey using 54 blue horizontal branch stars in the Milky Way halo as background sources for detecting gas flows at the disk–halo interface. Distance measurements to high-latitude (b > 60°) background stars at 3.1–1... Read More about Galactic Gas Flows from Halo to Disk: Tomography and Kinematics at the Milky Way’s Disk–Halo Interface.

Space Telescope and Optical Reverberation Mapping Project. VIII. Time Variability of Emission and Absorption in NGC 5548 Based on Modeling the Ultraviolet Spectrum (2019)
Journal Article
Kriss, G., De Rosa, G., Ely, J., Peterson, B., Kaastra, J., Mehdipour, M., …Zu, Y. (2019). Space Telescope and Optical Reverberation Mapping Project. VIII. Time Variability of Emission and Absorption in NGC 5548 Based on Modeling the Ultraviolet Spectrum. Astrophysical Journal, 881(2), https://doi.org/10.3847/1538-4357/ab3049

We model the ultraviolet spectra of the Seyfert 1 galaxy NGC 5548 obtained with the Hubble Space Telescope during the 6 month reverberation mapping campaign in 2014. Our model of the emission from NGC 5548 corrects for overlying absorption and deblen... Read More about Space Telescope and Optical Reverberation Mapping Project. VIII. Time Variability of Emission and Absorption in NGC 5548 Based on Modeling the Ultraviolet Spectrum.

HALO7D II: The Halo Velocity Ellipsoid and Velocity Anisotropy with Distant Main-sequence Stars (2019)
Journal Article
Cunningham, E. C., Deason, A. J., Sanderson, R. E., Sohn, S. T., Anderson, J., Guhathakurta, P., …Wetzel, A. (2019). HALO7D II: The Halo Velocity Ellipsoid and Velocity Anisotropy with Distant Main-sequence Stars. Astrophysical Journal, 879(2), Article 120. https://doi.org/10.3847/1538-4357/ab24cd

The Halo Assembly in Lambda Cold Dark Matter: Observations in 7 Dimensions (HALO7D) data set consists of Keck II/DEIMOS spectroscopy and Hubble Space Telescope–measured proper motions of Milky Way halo main-sequence turnoff stars in the CANDELS field... Read More about HALO7D II: The Halo Velocity Ellipsoid and Velocity Anisotropy with Distant Main-sequence Stars.