Search Publications
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…
HST/COS Observations of Quasar Outflows in the 500-1050 Å Rest Frame. VI. Wide, Energetic Outflows in SDSS J0755+2306
Xu, Xinfeng; Kriss, Gerard A.; Arav, Nahum +2 more
We present the analysis of two outflows (S1 at -5500 km s-1 and S2 at -9700 km s-1) seen in recent Hubble Space Telescope/Cosmic Origins Spectrograph observations of quasar SDSS J0755+2306 (z = 0.854). The outflows are detected as absorption troughs from both high-ionization species, including N III, O III, and S IV, and very…
Artificial Intelligence-Assisted Inversion (AIAI) of Synthetic Type Ia Supernova Spectra
Wang, Lifan; Hu, Lei; Chen, Xingzhuo
We generate ∼100,000 model spectra of Type 1a supernovae (SNe Ia) to form a spectral library for the purpose of building an artificial intelligence-assisted inversion (AIAI) algorithm for theoretical models. As a first attempt, we restrict our studies to the time around B-band maximum and compute theoretical spectra with a broad spectral wavelengt…
AstroSat UVIT Detections of Chandra X-Ray Sources in M31
Chen, Y.; Leahy, D. A.
An ultraviolet (UV) survey of M31 has been carried out during 2017-19 with the Ultra-Violet Imaging Telescope (UVIT) instrument on board the AstroSat Observatory. Here we match the M31 UVIT source catalog with the Chandra source catalog. We find 67 UVIT/Chandra sources detected in a varying number of UV and X-ray bands. The UV and X-ray photometry…
Identification of Single Spectral Lines through Supervised Machine Learning in a Large HST Survey (WISP): A Pilot Study for Euclid and WFIRST
Rodighiero, G.; Malkan, M.; Henry, A. +13 more
Future surveys focusing on understanding the nature of dark energy (e.g., Euclid and WFIRST) will cover large fractions of the extragalactic sky in near-IR slitless spectroscopy. These surveys will detect a large number of galaxies that will have only one emission line in the covered spectral range. In order to maximize the scientific return of th…