Search Publications
The Density of Mid-sized Kuiper Belt Object 2002 UX25 and the Formation of the Dwarf Planets
Brown, M. E.
The formation of the largest objects in the Kuiper belt, with measured densities of ~1.5 g cm-3 and higher, from the coagulation of small bodies, with measured densities below 1 g cm-3, is difficult to explain without invoking significant porosity in the smallest objects. If such porosity does occur, measured densities should…
Large scale IRAM 30 m CO-observations in the giant molecular cloud complex W43
Hill, T.; Schneider, N.; Ossenkopf, V. +11 more
We aim to fully describe the distribution and location of dense molecular clouds in the giant molecular cloud complex W43. It was previously identified as one of the most massive star-forming regions in our Galaxy. To trace the moderately dense molecular clouds in the W43 region, we initiated W43-HERO, a large program using the IRAM 30 m telescope…
The Origin of Dust in Early-type Galaxies and Implications for Accretion onto Supermassive Black Holes
Storchi-Bergmann, Thaisa; Martini, Paul; Dicken, Daniel
We have conducted an archival Spitzer study of 38 early-type galaxies in order to determine the origin of the dust in approximately half of this population. Our sample galaxies generally have good wavelength coverage from 3.6 µm to 160 µm, as well as visible-wavelength Hubble Space Telescope (HST) images. We use the Spitzer data to est…
Obscuration effects in super-soft-source X-ray spectra
Behar, E.; Ness, J. -U.; Henze, M. +11 more
Context. Super-soft-source (SSS) X-ray spectra are blackbody-like spectra with effective temperatures ~3-7 × 105 K and luminosities of 1035-38 erg s-1. Grating spectra of SSS and novae in outburst that show SSS type spectra display atmospheric absorption lines. Radiation transport atmosphere models can be used to d…
PS1-12sk is a Peculiar Supernova from a He-rich Progenitor System in a Brightest Cluster Galaxy Environment
Price, P. A.; Berger, E.; Kirshner, R. P. +29 more
We report on our discovery and observations of the Pan-STARRS1 supernova (SN) PS1-12sk, a transient with properties that indicate atypical star formation in its host galaxy cluster or pose a challenge to popular progenitor system models for this class of explosion. The optical spectra of PS1-12sk classify it as a Type Ibn SN (SN Ibn cf. SN 2006jc)…
Discovery of the Recombining Plasma in the South of the Galactic Center: A Relic of the Past Galactic Center Activity?
Koyama, K.; Tanaka, T.; Murakami, H. +5 more
We report Suzaku results for soft X-ray emission to the south of the Galactic center (GC). The emission (hereafter "GC South") has an angular size of ~42' × 16' centered at (l, b) ~ (0.°0, - 1.°4) and is located in the largely extended Galactic ridge X-ray emission (GRXE). The X-ray spectrum of GC South exhibits emission lines from highly ionized …
Is the black hole in NGC 1277 really overmassive?
Emsellem, Eric
A recent claim has been made by van den Bosch et al. that the fast-rotator galaxy NGC 1277 hosts an overmassive black hole with a mass (1.7 × 1010 M⊙) larger than half its (central) stellar spheroid mass. We revisit this claim here by examining the predictions from simple dynamical realizations based on new multi-Gaussian exp…
The HETDEX Pilot Survey. IV. The Evolution of [O II] Emitting Galaxies from z ~ 0.5 to z ~ 0
Finkelstein, Steven L.; Schneider, Donald P.; Blanc, Guillermo A. +10 more
We present an analysis of the luminosities and equivalent widths of the 284 z < 0.56 [O II]-emitting galaxies found in the 169 arcmin2 pilot survey for the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX). By combining emission-line fluxes obtained from the Mitchell spectrograph on the McDonald 2.7 m telescope with deep broadba…
Detection of Substructure in the Gravitationally Lensed Quasar MG0414+0534 Using Mid-infrared and Radio VLBI Observations
Kochanek, Christopher S.; Agol, Eric; MacLeod, Chelsea L. +1 more
We present 11.2 µm observations of the gravitationally lensed, radio-loud zs = 2.64 quasar MG0414+0534, obtained using the Michelle camera on Gemini North. We find a flux ratio anomaly of A2/A1 = 0.93 ± 0.02 for the quasar images A1 and A2. When combined with the 11.7 µm measurements from Minezaki et al., the A2/A1 flux rati…
The Atacama Cosmology Telescope: Relation between Galaxy Cluster Optical Richness and Sunyaev-Zel'dovich Effect
Hilton, Matt; Hasselfield, Matthew; Sifón, Cristóbal +33 more
We present the measured Sunyaev-Zel'dovich (SZ) flux from 474 optically selected MaxBCG clusters that fall within the Atacama Cosmology Telescope (ACT) Equatorial survey region. The ACT Equatorial region used in this analysis covers 510 deg2 and overlaps Stripe 82 of the Sloan Digital Sky Survey. We also present the measured SZ flux sta…