Search Publications
COS-burst: Observations of the Impact of Starburst-driven Winds on the Properties of the Circum-galactic Medium
Heckman, Timothy; Wild, Vivienne; Borthakur, Sanchayeeta +2 more
We report on observations made with the Cosmic Origins Spectrograph (COS) on the Hubble Space Telescope (HST) using background quasi-stellar objects to probe the circum-galactic medium (CGM) around 17 low-redshift galaxies that are undergoing or have recently undergone a strong starburst (the COS-Burst program). The sightlines extend out to roughl…
Does a Differentiated, Carbonate-rich, Rocky Object Pollute the White Dwarf SDSS J104341.53+085558.2?
Dufour, P.; Melis, Carl
We present spectroscopic observations of the dust- and gas-enshrouded, polluted, single white dwarf star SDSS J104341.53+085558.2 (hereafter SDSS J1043+0855). Hubble Space Telescope Cosmic Origins Spectrograph far-ultraviolet spectra combined with deep Keck HIRES optical spectroscopy reveal the elements C, O, Mg, Al, Si, P, S, Ca, Fe, and Ni and e…
Witnessing the growth of the nearest galaxy cluster: thermodynamics of the Virgo Cluster outskirts
Simionescu, A.; Allen, S. W.; Werner, N. +2 more
We present results from Suzaku Key Project observations of the Virgo Cluster, the nearest galaxy cluster to us, mapping its X-ray properties along four long 'arms' extending beyond the virial radius. The entropy profiles along all four azimuths increase with radius, then level out beyond ∼0.5r200, while the average pressure at large rad…
Active galactic nuclei vs. host galaxy properties in the COSMOS field
Berta, S.; Pozzi, F.; Salvato, M. +13 more
Context. The coeval active galactic nuclei (AGN) and galaxy evolution, and the observed local relations between super massive black holes (SMBHs) and galaxy properties suggest some sort of connection or feedback between SMBH growth (I.e., AGN activity) and galaxy build-up (I.e., star formation history).
Aims: We looked for correlations betwee…
Microlensing of Extremely Magnified Stars near Caustics of Galaxy Clusters
Miralda-Escudé, Jordi; Dai, Liang; Venumadhav, Tejaswi
Recent observations of lensed galaxies at cosmological distances have detected individual stars that are extremely magnified when crossing the caustics of lensing clusters. In idealized cluster lenses with smooth mass distributions, two images of a star of radius R approaching a caustic brighten as {t}-1/2 and reach a peak magnification…
The mean star formation rates of unobscured QSOs: searching for evidence of suppressed or enhanced star formation
Alexander, D. M.; Wang, L.; De Zotti, G. +15 more
We investigate the mean star formation rates (SFRs) in the host galaxies of ∼3000 optically selected quasi-stellar objects (QSOs) from the Sloan Digital Sky Survey within the Herschel-ATLAS fields, and a radio-luminous subsample covering the redshift range of z = 0.2-2.5. Using Wide-field Infrared Survey Explorer (WISE) and Herschel photometry (12…
Zodiacal Exoplanets in Time (ZEIT). V. A Uniform Search for Transiting Planets in Young Clusters Observed by K2
Vanderburg, Andrew; Rizzuto, Aaron C.; Kraus, Adam L. +2 more
Detection of transiting exoplanets around young stars is more difficult than for older systems owing to increased stellar variability. Nine young open cluster planets have been found in the K2 data, but no single analysis pipeline identified all planets. We have developed a transit search pipeline for young stars that uses a transit-shaped notch a…
Impact of neutrino properties on the estimation of inflationary parameters from current and future observations
Ho, Shirley; Mena, Olga; Gerbino, Martina +4 more
We study the impact of assumptions about neutrino properties on the estimation of inflationary parameters from cosmological data, with a specific focus on the allowed contours in the ns/r plane, where ns is the scalar spectral index and r is the tensor-to-scalar ratio. We study the following neutrino properties: (i) the total…
Lensing Constraints on the Mass Profile Shape and the Splashback Radius of Galaxy Clusters
Umetsu, Keiichi; Diemer, Benedikt
The lensing signal around galaxy clusters can, in principle, be used to test detailed predictions for their average mass profile from numerical simulations. However, the intrinsic shape of the profiles can be smeared out when a sample that spans a wide range of cluster masses is averaged in physical length units. This effect especially conceals ra…
The Dragonfly Nearby Galaxies Survey. III. The Luminosity Function of the M101 Group
van Dokkum, Pieter; Abraham, Roberto; Danieli, Shany +4 more
We obtained follow-up HST observations of the seven low surface brightness galaxies discovered with the Dragonfly Telephoto Array in the field of the massive spiral galaxy M101. Out of the seven galaxies, only three were resolved into stars and are potentially associated with the M101 group at D = 7 Mpc. Based on HST ACS photometry in the broad F6…