Search Publications
The Rotation of the Hot Gas around the Milky Way
Bregman, Joel N.; Miller, Matthew J.; Hodges-Kluck, Edmund J.
The hot gaseous halos of galaxies likely contain a large amount of mass and are an integral part of galaxy formation and evolution. The Milky Way has a 2× {10}6 K halo that is detected in emission and by absorption in the O vii resonance line against bright background active galactic nuclei (AGNs), and for which the best current model i…
Candidate Gravitationally Lensed Dusty Star-forming Galaxies in the Herschel Wide Area Surveys
Ivison, R. J.; Frayer, D. T.; Omont, A. +21 more
We present a list of candidate gravitationally lensed dusty star-forming galaxies (DSFGs) from the HerMES Large Mode Survey and the Herschel Stripe 82 Survey. Together, these partially overlapping surveys cover 372 deg2 on the sky. After removing local spiral galaxies and known radio-loud blazars, our candidate list of lensed DSFGs is c…
Simultaneous IRIS and Hinode/EIS Observations and Modelling of the 2014 October 27 X2.0 Class Flare
Mason, H. E.; Golub, L.; Del Zanna, G. +5 more
We present a study of the X2-class flare which occurred on 2014 October 27 and was observed with the Interface Region Imaging Spectrograph (IRIS) and the EUV Imaging Spectrometer (EIS) on board the Hinode satellite. Thanks to the high cadence and spatial resolution of the IRIS and EIS instruments, we are able to compare simultaneous observations o…
The Interaction of the Fermi Bubbles with the Milky Way’s Hot Gas Halo
Bregman, Joel N.; Miller, Matthew J.
The Fermi bubbles are two lobes filled with non-thermal particles that emit gamma rays, extend ≈ 10 {{kpc}} vertically from the Galactic center, and formed from either nuclear star formation or accretion activity on Sgr A*. Simulations predict a range of shock strengths as the bubbles expand into the surrounding hot gas halo ({T}{halo}≈…
The NuSTAR Extragalactic Surveys: The Number Counts of Active Galactic Nuclei and the Resolved Fraction of the Cosmic X-Ray Background
Harrison, F. A.; Hornstrup, A.; Stern, D. +41 more
We present the 3-8 keV and 8-24 keV number counts of active galactic nuclei (AGNs) identified in the Nuclear Spectroscopic Telescope Array (NuSTAR) extragalactic surveys. NuSTAR has now resolved 33%-39% of the X-ray background in the 8-24 keV band, directly identifying AGNs with obscuring columns up to ∼ {10}25 {{cm}}-2. In t…
Evidence for a Systematic Offset of -0.25 mas in the Gaia DR1 Parallaxes
Torres, Guillermo; Stassun, Keivan G.
We test the parallaxes reported in the Gaia first data release using the sample of eclipsing binaries with accurate, empirical distances from Stassun & Torres. We find an average offset of -0.25 ± 0.05 mas in the sense of the Gaia parallaxes being too small (I.e., the distances too long). The offset does not depend strongly on obvious paramete…
Lyman Continuum Escape Fraction of Star-forming Dwarf Galaxies at z ∼ 1
Teplitz, Harry I.; Rutkowski, Michael J.; Scarlata, Claudia +10 more
To date, no direct detection of Lyman continuum emission has been measured for intermediate-redshift (z∼ 1) star-forming galaxies. We combine Hubble Space Telescope grism spectroscopy with GALEX UV and ground-based optical imaging to extend the search for escaping Lyman continuum to a large (∼600) sample of z∼ 1 low-mass ({log}(\bar{M}) ≃ 9.3{M}
The Afterglow and Early-type Host Galaxy of the Short GRB 150101B at z = 0.1343
Berger, E.; Smith, N.; Zaritsky, D. +14 more
We present the discovery of the X-ray and optical afterglows of the short-duration GRB 150101B, pinpointing the event to an early-type host galaxy at z = 0.1343 ± 0.0030. This makes GRB 150101B the most nearby short gamma-ray burst (GRB) with an early-type host galaxy discovered to date. Fitting the spectral energy distribution of the host galaxy …
An Ultraviolet Spectrum of the Tidal Disruption Flare ASASSN-14li
Fruchter, Andrew S.; Filippenko, Alexei V.; Ramirez-Ruiz, Enrico +18 more
We present a Hubble Space Telescope Space Telescope Imaging Spectrograph spectrum of ASASSN-14li, the first rest-frame ultraviolet (UV) spectrum of a tidal disruption flare (TDF). The underlying continuum is well fit by a blackbody with {T}{UV}=3.5× {10}4 K, an order of magnitude smaller than the temperature inferred from X-r…
Evolution of Thermally Pulsing Asymptotic Giant Branch Stars. V. Constraining the Mass Loss and Lifetimes of Intermediate-mass, Low-metallicity AGB Stars
Williams, Benjamin F.; Dolphin, Andrew; Girardi, Léo +4 more
Thermally pulsing asymptotic giant branch (TP-AGB) stars are relatively short lived (less than a few Myr), yet their cool effective temperatures, high luminosities, efficient mass loss, and dust production can dramatically affect the chemical enrichment histories and the spectral energy distributions of their host galaxies. The ability to accurate…