Search Publications
z ∼ 2: An Epoch of Disk Assembly
Trump, Jonathan R.; Weiner, Benjamin J.; Pacifici, Camilla +8 more
We explore the evolution of the internal gas kinematics of star-forming galaxies from the peak of cosmic star formation at z∼ 2 to today. Measurements of galaxy rotation velocity V rot, which quantify ordered motions, and gas velocity dispersion {σ }g, which quantify disordered motions, are adopted from the DEEP2 and SIGMA su…
The global meter-level shape model of comet 67P/Churyumov-Gerasimenko
Jorda, L.; Lara, L. M.; Bertaux, J. -L. +42 more
We performed a stereo-photogrammetric (SPG) analysis of more than 1500 Rosetta/OSIRIS NAC images of comet 67P/Churyumov-Gerasimenko (67P). The images with pixel scales in the range 0.2-3.0 m/pixel were acquired between August 2014 and February 2016. We finally derived a global high-resolution 3D description of 67P's surface, the SPG SHAP7 shape mo…
Towards a Unified View of Inhomogeneous Stellar Winds in Isolated Supergiant Stars and Supergiant High Mass X-Ray Binaries
Fürst, Felix; Kretschmar, Peter; Wilms, Jörn +13 more
Massive stars, at least ∼10 times more massive than the Sun, have two key properties that make them the main drivers of evolution of star clusters, galaxies, and the Universe as a whole. On the one hand, the outer layers of massive stars are so hot that they produce most of the ionizing ultraviolet radiation of galaxies; in fact, the first massive…
X-Ray Brightening and UV Fading of Tidal Disruption Event ASASSN-15oi
Cenko, S. B.; Arcavi, I.; Gezari, S.
We present late-time observations by Swift and XMM-Newton of the tidal disruption event (TDE) ASASSN-15oi that reveal that the source brightened in the X-rays by a factor of ∼10 one year after its discovery, while it faded in the UV/optical by a factor of ∼100. The XMM-Newton observations measure a soft X-ray blackbody component with {{kT}}{b…
iPTF Discovery of the Rapid “Turn-on” of a Luminous Quasar
Cenko, S. B.; Kulkarni, S. R.; Nugent, P. E. +13 more
We present a radio-quiet quasar at z = 0.237 discovered “turning on” by the intermediate Palomar Transient Factory (iPTF). The transient, iPTF 16bco, was detected by iPTF in the nucleus of a galaxy with an archival Sloan Digital Sky Survey spectrum with weak narrow-line emission characteristic of a low-ionization nuclear emission-line region (LINE…
Evidence for interacting dark energy from BOSS
Ferreira, Elisa G. M.; Quintin, Jerome; Costa, André A. +2 more
The result presented by the BOSS-SDSS Collaboration measuring the baryon acoustic oscillations of the Lyman-alpha forest from high-redshift quasars indicates a 2.5 σ departure from the standard Λ -cold-dark-matter model. This is the first time that the evolution of dark energy at high redshifts has been measured, and the current results cannot be …
Evidence for a Hard Ionizing Spectrum from a z = 6.11 Stellar Population
Kollmeier, Juna A.; Stark, Daniel P.; Newman, Andrew B. +4 more
We present the Magellan/FIRE detection of highly ionized C IV λ1550 and O III]λ1666 in a deep infrared spectrum of the z = 6.11 gravitationally lensed low-mass galaxy RXC J2248.7-4431-ID3, which has previously known Lyα. No corresponding emission is detected at the expected location of He II λ1640. The upper limit on He II, paired with detection o…
Molecular gas in the Herschel-selected strongly lensed submillimeter galaxies at z 2-4 as probed by multi-J CO lines
Smail, I.; Omont, A.; Cooray, A. +18 more
We present the IRAM-30 m observations of multiple-J CO (Jup mostly from 3 up to 8) and [C I](3P2 → 3P1) ([C I](2-1) hereafter) line emission in a sample of redshift ~2-4 submillimeter galaxies (SMGs). These SMGs are selected among the brightest-lensed galaxies discovered in the Herschel-Astrop…
Galactic rotation in Gaia DR1
Bovy, Jo
The spatial variations of the velocity field of local stars provide direct evidence of Galactic differential rotation. The local divergence, shear and vorticity of the velocity field - the traditional Oort constants - can be measured based purely on astrometric measurements and in particular depend linearly on proper motion and parallax. I use dat…
The Complete Calibration of the Color-Redshift Relation (C3R2) Survey: Survey Overview and Data Release 1
Castander, Francisco J.; Cohen, Judith G.; Paltani, Stéphane +4 more
A key goal of the Stage IV dark energy experiments Euclid, LSST, and WFIRST is to measure the growth of structure with cosmic time from weak lensing analysis over large regions of the sky. Weak lensing cosmology will be challenging: in addition to highly accurate galaxy shape measurements, statistically robust and accurate photometric redshift (ph…