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…
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…
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…
Relations between the Sizes of Galaxies and Their Dark Matter Halos at Redshifts 0 < z < 3
Pérez-González, Pablo G.; Ferguson, Henry C.; van der Wel, Arjen +6 more
We derive relations between the effective radii R eff of galaxies and the virial radii R 200c of their dark matter halos over the redshift range 0 < z < 3. For galaxies, we use the measured sizes from deep images taken with Hubble Space Telescope for the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey; f…
Connection between Stellar Mass Distributions within Galaxies and Quenching Since z = 2
Tacchella, Sandro; Renzini, Alvio; Onodera, Masato +5 more
We study the history from z∼ 2 to z∼ 0 of the stellar mass assembly of quiescent and star-forming galaxies in a spatially resolved fashion. For this purpose, we use multi-wavelength imaging data from the Hubble Space Telescope (HST) over the GOODS fields and the Sloan Digital Sky Survey (SDSS) for the local population. We present the radial stella…
Gemini Near Infrared Field Spectrograph Observations of the Seyfert 2 Galaxy Mrk 573: In Situ Acceleration of Ionized and Molecular Gas off Fueling Flows
Kraemer, S. B.; Crenshaw, D. M.; Storchi-Bergmann, T. +9 more
We present near-infrared and optical emission-line and stellar kinematics of the Seyfert 2 galaxy Mrk 573 using the Near-Infrared Field Spectrograph (NIFS) at Gemini North and Dual Imaging Spectrograph at Apache Point Observatory, respectively. By obtaining full kinematic maps of the infrared ionized and molecular gas and stellar kinematics in a ∼…
Survey of Cold Water Lines in Protoplanetary Disks: Indications of Systematic Volatile Depletion
van Dishoeck, Ewine F.; Fedele, Davide; Lis, Dariusz C. +11 more
We performed very deep searches for 2 ground-state water transitions in 13 protoplanetary disks with the HIFI instrument on board the Herschel Space Observatory, with integration times up to 12 hr per line. We also searched for, with shallower integrations, two other water transitions that sample warmer gas. The detection rate is low, and the uppe…
Spectral Changes in the Hyperluminous Pulsar in NGC 5907 as a Function of Super-orbital Phase
Harrison, F. A.; Stern, D.; Bachetti, M. +5 more
We present broadband, multi-epoch X-ray spectroscopy of the pulsating ultra-luminous X-ray source (ULX) in NGC 5907. Simultaneous XMM-Newton and NuSTAR data from 2014 are best described by a multicolor blackbody model with a temperature gradient as a function of accretion disk radius significantly flatter than expected for a standard thin accretio…