519 citations · 1.9k across the 17 of their papers we have counts for
17 papers
Agnostic Stacking of Intergalactic Doublet Absorption: Measuring the NeVIII Population
Stephan Frank, Matthew M. Pieri, Smita Mathur +2
We present a blind search for doublet intergalactic metal absorption with a method dubbed `agnostic stacking'. Using a forward-modelling framework we combine this with direct detec…
Ultraviolet Emission-Line Correlations in Hubble/COS Spectra of Active Galactic Nuclei: Single-Epoch Black Hole Masses
Evan M. Tilton, J. Michael Shull
Effective methods of measuring supermassive black hole masses in active galactic nuclei (AGN) are of critical importance to studies of galaxy evolution. While there has been much s…
The Escape Fraction of Ionizing Radiation from Galaxies
Andrew Benson, Aparna Venkatesan, J. Michael Shull
The escape of ionizing radiation from galaxies plays a critical role in the evolution of gas in galaxies, and the heating and ionization history of the intergalactic medium. We pre…
The low-redshift intergalactic medium as seen in archival legacy Hubble/STIS and FUSE data
Evan M. Tilton, Charles W. Danforth, J. Michael Shull +1
We present a comprehensive catalog of ultraviolet HST/STIS and FUSE absorbers in the low-redshift IGM at z<0.4. The catalog draws from the extensive literature on IGM absorption, a…
Detecting the warm-hot intergalactic medium through X-ray absorption lines
Yangsen Yao, J. Michael Shull, Q. Daniel Wang +1
The warm-hot intergalactic medium (WHIM) at temperatures 1E5-1E7 K is believed to contain 30-50% of the baryons in the local universe. However, all current X-ray detections of the…
The Baryon Census in a Multiphase Intergalactic Medium: 30% of the Baryons May Still Be Missing
J. Michael Shull, Britton D. Smith, Charles W. Danforth
For low-redshift cosmology and galaxy formation rates, it is important to account for all the baryons synthesized in the Big Bang. Although galaxies and clusters contain 10% of the…
Ultraviolet and X-ray Variability of the Seyfert 1.5 Galaxy Markarian 817
Lisa M. Winter, Charles Danforth, Ranjan Vasudevan +9
We present an investigation of the ultraviolet and X-ray spectra of the Seyfert 1.5 galaxy Markarian 817. The ultraviolet analysis includes two recent observations taken with the C…
Hubble/COS Observations of the Quasar HE 2347-4342: Probing the Epoch of He II Patchy Reionization at Redshifts z = 2.4-2.9
Michael Shull, Kevin France, Charles Danforth +2
We report ultraviolet spectra of the high-redshift (z_em = 2.9) quasar, HE 2347-4342, taken by the Cosmic Origins Spectrograph (COS) on the Hubble Space Telescope (HST). Spectra in…
Cosmic Origins Spectrograph and FUSE Observations of T ~ 10^5 K Gas In A Nearby Galaxy Filament
Anand Narayanan, Bart P. Wakker, Blair D. Savage +4
We present a detection of a broad Ly-alpha absorber (BLA) with a matching O VI line in the nearby universe. The BLA is detected at z = 0.01028 in the high S/N spectrum of Mrk 290 o…
HST/COS Observations of the Ly alpha Forest toward the BL Lac Object 1ES1553+113
Charles W. Danforth, Brian A. Keeney, John T. Stocke +2
We present new far-ultraviolet spectra from the Cosmic Origins Spectrograph (HST/COS) of the BL Lac object 1ES1553+113 covering the wavelength range 1135-1795 A. The data show a sm…
How well do cosmological simulations reproduce individual-halo properties?
M. Trenti, B. D. Smith, E. J. Hallman +2
Cosmological simulations of galaxy formation often rely on prescriptions for star formation and feedback that depend on halo properties such as halo mass, central over-density, and…
Broad HI Absorbers as Metallicity-Independent Tracers of the Warm-Hot Intergalactic Medium
Charles W. Danforth, John T. Stocke, J. Michael Shull
Thermally broadened Ly alpha absorbers (BLAs) offer an alternative method to highly-ionized metal lines for tracing the WHIM. We compile a catalog of reliable BLA candidates along…
What is the Total Deuterium Abundance in the Local Galactic Disk?
Jeffrey L. Linsky, Bruce T. Draine, H. W. Moos +14
Analyses of spectra obtained with the Far Ultraviolet Spectroscopic Explorer (FUSE) satellite, together with spectra from the Copernicus and IMAPS instruments, reveal an unexplaine…
Optical Structure and Proper-Motion Age of the Oxygen-rich Supernova Remnant 1E 0102-7219 in the Small Magellanic Cloud
Steven L. Finkelstein, Jon A. Morse, James C. Green +12
We present new optical emission-line images of the young SNR 1E 0102-7219 (E0102) in the SMC obtained with the HST Advanced Camera for Surveys (ACS). E0102 is a member of the oxyge…
Cosmological Effects of the First Stars: Evolving Spectra of Population III
Jason Tumlinson, J. Michael Shull, Aparna Venkatesan
The first stars hold intrinsic interest for their uniqueness and for their potential importance to galaxy formation, chemical enrichment, and feedback on the intergalactic medium (…
Far Ultraviolet Spectroscopy of the Intergalactic and Interstellar Absorption Toward 3C 273
K. R. Sembach, J. C. Howk, B. D. Savage +2
We present Far Ultraviolet Spectroscopic Explorer (FUSE) observations of the molecular, neutral atomic, weakly ionized, and highly ionized components of the interstellar and interg…
Zero-Metallicity Stars and the Effects of the First Stars on Reionization
Jason Tumlinson, J. Michael Shull
We present stellar structure and atmosphere models of metal-free stars and examine them from a cosmological point of view. Metal-free stars exhibit high effective temperatures and…