Search Publications
Deciphering the Large-scale Environment of Radio Galaxies in the Local Universe. II. A Statistical Analysis of Environmental Properties
Capetti, A.; Tramacere, A.; Campana, R. +6 more
In our previous analysis we investigated the large-scale environment of two samples of radio galaxies (RGs) in the local universe (I.e., with redshifts zsrc ≤ 0.15), classified as FR I and FR II on the basis of their radio morphology. The analysis was carried out using (I) extremely homogeneous catalogs and (II) a new method, known as c…
In the Trenches of the Solar-Stellar Connection. I. Ultraviolet and X-Ray Flux-Flux Correlations across the Activity Cycles of the Sun and Alpha Centauri AB
Ayres, Thomas R.
This study focuses on high-energy proxies of stellar magnetic activity over long-term starspot cycles of three low-activity Sun-like stars: α Centauri A (HD 128620: G2 V), α Cen B (HD 128621: K1 V), and the Sun itself. Data sets include: daily solar ultraviolet irradiance spectra and X-ray fluxes from the Solar Radiation and Climate Experiment, du…
HST/COS Observations of Quasar Outflows in the 500-1050 Å Rest Frame. II. The Most Energetic Quasar Outflow Measured to Date
Xu, Xinfeng; Kriss, Gerard A.; Arav, Nahum +2 more
We present a study of the BAL outflows seen in quasar SDSS J1042+1646 (z = 0.978) in the rest-frame 500-1050 Å (EUV500) region. The results are based on the analysis of recent Hubble Space Telescope/Cosmic Origins Spectrograph observations. Five outflow systems are identified, where, in total, they include ∼70 outflow troughs from ionic transition…
Matched Photometric Catalogs of GALEX UV Sources with Gaia DR2 and SDSS DR14 Databases (GUVmatch)
Bianchi, Luciana; Shiao, Bernard
We have matched the ultraviolet (UV) sources in GUVcat_AIS with optical databases that have similar depth and wide sky coverage. GUVcat_AIS has Galaxy Evolution Explorer (GALEX) far-UV (FUV, λeff ∼ 1528 Å) and near-UV (NUV, λeff ∼ 2310 Å) photometry of ≈83 million sources, covering 24,788 square degrees of the sky, with a typ…
Forecasting Chemical Abundance Precision for Extragalactic Stellar Archaeology
Ting, Yuan-Sen; Weisz, Daniel R.; Sandford, Nathan R.
Increasingly powerful and multiplexed spectroscopic facilities promise detailed chemical abundance patterns for millions of resolved stars in galaxies beyond the Milky Way (MW). Here, we employ the Cramér-Rao lower bound (CRLB) to forecast the precision to which stellar abundances for metal-poor, low-mass stars outside the MW can be measured for 4…
The Sloan Digital Sky Survey Reverberation Mapping Project: the XMM-Newton X-Ray Source Catalog and Multiband Counterparts
Green, Paul J.; Shen, Yue; Nandra, Kirpal +10 more
The XMM-RM project was designed to provide X-ray coverage of the Sloan Digital Sky Survey Reverberation Mapping (SDSS-RM) field. Forty-one XMM-Newton exposures, placed surrounding the Chandra AEGIS field, were taken, covering an area of 6.13 deg2 and reaching a nominal exposure depth of ∼15 ks. We present an X-ray catalog of 3553 source…
HST/COS Observations of Quasar Outflows in the 500-1050 Å Rest Frame. IV. The Largest Broad Absorption Line Acceleration
Xu, Xinfeng; Kriss, Gerard A.; Arav, Nahum +2 more
We present an analysis of the broad absorption line (BAL) velocity shift that appeared in one of the outflow systems in quasar SDSS J1042+1646. Observations were taken by the Hubble Space Telescope/Cosmic Origins Spectrograph in 2011 and 2017 in the 500-1050 Å rest frame. The outflow's velocity centroid shifted by ∼-1550 km s-1 from -19…
HST/COS Observations of Quasar Outflows in the 500-1050 Å Rest Frame. III. Four Similar Outflows in 2MASS J1051+1247 with Enough Energy to Be Major Contributors to AGN Feedback
Xu, Xinfeng; Kriss, Gerard A.; Arav, Nahum +2 more
We detect four very energetic outflows in the Hubble Space Telescope/Cosmic Origins Spectrograph spectra of quasar 2MASS J1051+1247 with a combined kinetic luminosity (\dot{E}_{K}) of 1046 erg s-1. Remarkable similarities are seen in these outflows: velocity centroids between 4900 and 5700 km s-1, distances from th…
HST/COS Observations of Quasar Outflows in the 500-1050 Å Rest Frame. V. Richness of Physical Diagnostics and Ionization Potential-dependent Velocity Shift in PKS J0352-0711
Xu, Xinfeng; Kriss, Gerard A.; Arav, Nahum +2 more
We analyze absorption troughs from two outflows within PKS J0352-0711 (S1 at -1950 km s-1 and S2 at -3150 km s-1) from spectra taken with Hubble Space Telescope/Cosmic Origins Spectrograph, which cover the diagnostic-rich 585-900 Å rest-frame wavelength range. In S2, for the first time we clearly detect absorption troughs fro…
Deuterated Polycyclic Aromatic Hydrocarbons in the Interstellar Medium: The C-D Band Strengths of Monodeuterated Species
Li, Aigen; Yang, X. J.; Glaser, R.
Deuterium (D) is one of the light elements created in the Big Bang. As the Galaxy evolves, the D/H abundance in the interstellar medium (ISM) decreases from its primordial value due to astration. However, the observed gas-phase D/H abundances of some sightlines in the local Galactic ISM are substantially lower than the expected reduction by astrat…