Search Publications
Radial Velocity Offsets Due to Mass Outflows and Extinction in Active Galactic Nuclei
Kraemer, S. B.; Crenshaw, D. M.; Mushotzky, R. F. +2 more
We present a study of the radial velocity offsets between narrow emission lines and host galaxy lines (stellar absorption and H I 21 cm emission) in Seyfert galaxies with observed redshifts less than 0.043. We find that 35% of the Seyferts in the sample show [O III] emission lines with blueshifts with respect to their host galaxies exceeding 50 km…
Coronal Rain as a Marker for Coronal Heating Mechanisms
Shibata, K.; Vissers, G.; Antolin, P.
Reported observations in Hα, Ca II H, and K or other chromospheric lines of coronal rain trace back to the days of the Skylab mission. Corresponding to cool and dense plasma, coronal rain is often observed falling down along coronal loops in active regions. A physical explanation for this spectacular phenomenon has been put forward thanks to numer…
Keck Spectroscopy of z > 1 Field Spheroidals: Dynamical Constraints on the Growth Rate of Red "Nuggets"
Treu, Tommaso; Ellis, Richard S.; Newman, Andrew B. +1 more
We present deep Keck spectroscopy for 17 morphologically selected field spheroidals in the redshift range 1.05 < z < 1.60 in order to investigate the continuity in physical properties between the claimed massive compact red galaxies ("nuggets") at z ~= 2 and well-established data for massive spheroidal galaxies below z ~= 1. By combining Kec…
The Herschel Virgo Cluster Survey . II. Truncated dust disks in H I-deficient spirals
Bomans, D. J.; Bianchi, S.; Fritz, J. +27 more
By combining Herschel-SPIRE observations obtained as part of the Herschel Virgo Cluster Survey with 21 cm Hi data from the literature, we investigate the role of the cluster environment on the dust content of Virgo spiral galaxies. We show for the first time that the extent of the dust disk is significantly reduced in Hi-deficient galaxies, follow…
A Deep Chandra X-Ray Spectrum of the Accreting Young Star TW Hydrae
Luna, G. J. M.; Cranmer, S. R.; Dupree, A. K. +2 more
We present X-ray spectral analysis of the accreting young star TW Hydrae from a 489 ks observation using the Chandra High Energy Transmission Grating. The spectrum provides a rich set of diagnostics for electron temperature Te , electron density Ne , hydrogen column density NH , relative elemental abundances, and v…
First observation of a mini-magnetosphere above a lunar magnetic anomaly using energetic neutral atoms
Barabash, Stas; Holmström, Mats; Futaana, Yoshifumi +7 more
The Sub-keV Atom Reflecting Analyzer (SARA) instrument on the Indian Chandrayaan-1 spacecraft has produced for the first time an image of a lunar magnetic anomaly in backscattered hydrogen atoms. The image shows that a partial void of the solar wind, a mini-magnetosphere, is formed above the strong magnetic anomaly near the Crisium antipode. The m…
On the stellar masses of IRAC detected Lyman Break Galaxies at z ~ 3
Magdis, G. E.; Rigopoulou, D.; Fazio, G. G. +1 more
We present results of a large survey of the mid-infrared (mid-IR) properties of 248 Lyman Break Galaxies (LBGs) with confirmed spectroscopic redshift using deep Spitzer/Infrared Array Camera (IRAC) observations in six cosmological fields. By combining the new mid-IR photometry with optical and near-infrared observations, we model the spectral ener…
HERschel Inventory of The Agents of Galaxy Evolution (HERITAGE): The Large Magellanic Cloud dust
Poglitsch, A.; van Loon, J. Th.; Bernard, J. -P. +52 more
The HERschel Inventory of The Agents of Galaxy Evolution (HERITAGE) of the Magellanic Clouds will use dust emission to investigate the life cycle of matter in both the Large and Small Magellanic Clouds (LMC and SMC). Using the Herschel Space Observatory's PACS and SPIRE photometry cameras, we imaged a 2° × 8° strip through the LMC, at a position a…
How unprecedented a solar minimum?
Luhmann, J. G.; Russell, C. T.; Jian, L. K.
The end of the current solar minimum is at least 2 years late, and indicators of solar and geomagnetic activity are approaching or are at their historical lows. We examine current indicators to determine how unprecedented this solar cycle might be, comment on possible earlier analogs to the current situation, and discuss attempts to predict future…
The Estimation of Star Formation Rates and Stellar Population Ages of High-redshift Galaxies from Broadband Photometry
Ferguson, Henry C.; Giavalisco, Mauro; Somerville, Rachel S. +2 more
We explore methods to improve the estimates of star formation rates and mean stellar population ages from broadband photometry of high-redshift star-forming galaxies. We use synthetic spectral templates with a variety of simple parametric star formation histories to fit broadband spectral energy distributions. These parametric models are used to i…