Search Publications
A Critical Assessment of Photometric Redshift Methods: A CANDELS Investigation
Papovich, Casey; Finkelstein, Steven L.; Barro, Guillermo +35 more
We present results from the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) photometric redshift methods investigation. In this investigation, the results from 11 participants, each using a different combination of photometric redshift code, template spectral energy distributions (SEDs), and priors, are used to examine the…
The COS-Halos Survey: Rationale, Design, and a Census of Circumgalactic Neutral Hydrogen
Tripp, Todd M.; Prochaska, J. Xavier; Sembach, Kenneth R. +11 more
We present the design and methods of the COS-Halos survey, a systematic investigation of the gaseous halos of 44 z = 0.15-0.35 galaxies using background QSOs observed with the Cosmic Origins Spectrograph aboard the Hubble Space Telescope. This survey has yielded 39 spectra of z em ~= 0.5 QSOs with S/N ~10-15 per resolution element. The …
The COS-Halos Survey: An Empirical Description of Metal-line Absorption in the Low-redshift Circumgalactic Medium
Tripp, Todd M.; Prochaska, J. Xavier; Tumlinson, Jason +4 more
We present the equivalent width and column density measurements for low and intermediate ionization states of the circumgalactic medium (CGM) surrounding 44 low-z, L ≈ L* galaxies drawn from the COS-Halos survey. These measurements are derived from far-UV transitions observed in HST/COS and Keck/HIRES spectra of background quasars within an impact…
A Systematic Retrieval Analysis of Secondary Eclipse Spectra. I. A Comparison of Atmospheric Retrieval Techniques
Knutson, Heather; Line, Michael R.; Kammer, Joshua A. +6 more
Exoplanet atmosphere spectroscopy enables us to improve our understanding of exoplanets just as remote sensing in our own solar system has increased our understanding of the solar system bodies. The challenge is to quantitatively determine the range of temperatures and molecular abundances allowed by the data, which is often difficult given the lo…
Global collapse of molecular clouds as a formation mechanism for the most massive stars
Avison, A.; André, Ph.; Schneider, N. +8 more
The relative importance of primordial molecular cloud fragmentation versus large-scale accretion still remains to be assessed in the context of massive core/star formation. Studying the kinematics of the dense gas surrounding massive-star progenitors can tell us the extent to which large-scale flow of material impacts the growth in mass of star-fo…
Two emission mechanisms in the Fermi Bubbles: A possible signal of annihilating dark matter
Slatyer, Tracy R.; Hooper, Dan
We study the variation of the spectrum of the Fermi Bubbles with Galactic latitude. Far from the Galactic plane (|b|≳ 30°), the observed gamma-ray emission is nearly invariant with latitude, and is consistent with arising from inverse Compton scattering of the interstellar radiation field by cosmic-ray electrons with an approximately power-law spe…
An old disk still capable of forming a planetary system
Zhang, Ke; Gorti, Uma; Henning, Thomas +11 more
From the masses of the planets orbiting the Sun, and the abundance of elements relative to hydrogen, it is estimated that when the Solar System formed, the circumstellar disk must have had a minimum mass of around 0.01 solar masses within about 100 astronomical units of the star. (One astronomical unit is the Earth-Sun distance.) The main constitu…
Planck intermediate results. V. Pressure profiles of galaxy clusters from the Sunyaev-Zeldovich effect
Böhringer, H.; Kneissl, R.; Dahle, H. +215 more
Taking advantage of the all-sky coverage and broadfrequency range of the Planck satellite, we study the Sunyaev-Zeldovich (SZ) and pressure profiles of 62 nearby massive clusters detected at high significance in the 14-month nominal survey. Careful reconstruction of the SZ signal indicates that most clusters are individually detected at least out …
Propagation of Interplanetary Coronal Mass Ejections: The Drag-Based Model
Möstl, C.; Temmer, M.; Rollett, T. +9 more
We present the "Drag-Based Model" (DBM) of heliospheric propagation of interplanetary coronal mass ejections (ICMEs). The DBM is based on the hypothesis that the driving Lorentz force, which launches a CME, ceases in the upper corona and that beyond a certain distance the dynamics becomes governed solely by the interaction of the ICME and the ambi…
A Herschel [C ii] Galactic plane survey. I. The global distribution of ISM gas components
Goldsmith, P. F.; Langer, W. D.; Pineda, J. L. +1 more
Context. The [C ii] 158 µm line is an important tool for understanding the life cycle of interstellar matter. Ionized carbon is present in a variety of phases of the interstellar medium (ISM), including the diffuse ionized medium, warm and cold atomic clouds, clouds in transition from atomic to molecular, and dense and warm photon dominated …