Science Archives Publication System

Computer Vision for the Solar Dynamics Observatory (SDO)

DOI: 10.1007/s11207-010-9697-y Bibcode: 2012SoPh..275...79M

Wiegelmann, T.; Hochedez, J. F.; Raouafi, N. -E. +22 more

In Fall 2008 NASA selected a large international consortium to produce a comprehensive automated feature-recognition system for the Solar Dynamics Observatory (SDO). The SDO data that we consider are all of the Atmospheric Imaging Assembly (AIA) images plus surface magnetic-field images from the Helioseismic and Magnetic Imager (HMI). We produce r…

2012 • Solar Physics

Hinode SOHO 90

Field Topology Analysis of a Long-lasting Coronal Sigmoid

DOI: 10.1088/0004-637X/744/1/78 Bibcode: 2012ApJ...744...78S

van Ballegooijen, A. A.; DeLuca, E. E.; Savcheva, A. S.

We present the first field topology analysis based on nonlinear force-free field (NLFFF) models of a long-lasting coronal sigmoid observed in 2007 February with the X-Ray Telescope on Hinode. The NLFFF models are built with the flux rope insertion method and give the three-dimensional coronal magnetic field as constrained by observed coronal loop …

2012 • The Astrophysical Journal

Hinode SOHO 90

The Extended Hubble Space Telescope Supernova Survey: The Rate of Core Collapse Supernovae to z ~ 1

DOI: 10.1088/0004-637X/757/1/70 Bibcode: 2012ApJ...757...70D

Mobasher, Bahram; Riess, Adam G.; Strolger, Louis-Gregory +3 more

We use a sample of 45 core collapse supernovae detected with the Advanced Camera for Surveys on board the Hubble Space Telescope to derive the core collapse supernova rate in the redshift range 0.1 < z < 1.3. In redshift bins centered on langzrang = 0.39, langzrang = 0.73, and langzrang = 1.11, we find rates of 3.00^+1.28 _{- 0.…}

2012 • The Astrophysical Journal

eHST 90

The nature of the interstellar medium of the starburst low-metallicity galaxy Haro 11: a multi-phase model of the infrared emission

DOI: 10.1051/0004-6361/201219818 Bibcode: 2012A&A...548A..20C

Cooray, A.; Lebouteiller, V.; Madden, S. C. +15 more

Context. The low-metallicity interstellar medium (ISM) is profoundly different from that of normal systems, being clumpy with low dust abundance and little CO-traced molecular gas. Yet many dwarf galaxies in the nearby universe are actively forming stars. As the complex ISM phases are spatially mixed with each other, detailed modeling is needed to…

2012 • Astronomy and Astrophysics

Herschel eHST 90

Low-mass X-Ray Binaries Indicate a Top-heavy Stellar Initial Mass Function in Ultracompact Dwarf Galaxies

DOI: 10.1088/0004-637X/747/1/72 Bibcode: 2012ApJ...747...72D

Mieske, Steffen; Kroupa, Pavel; Pflamm-Altenburg, Jan +1 more

It has been shown before that the high mass-to-light ratios of ultracompact dwarf galaxies (UCDs) can be explained if their stellar initial mass function (IMF) was top-heavy, i.e., that the IMF was skewed toward high-mass stars. In this case, neutron stars (NSs) and black holes would provide unseen mass in the UCDs. In order to test this scenario …

2012 • The Astrophysical Journal

eHST 90

The Pair Fraction of Massive Galaxies at 0 <= z <= 3

DOI: 10.1088/0004-637X/744/2/85 Bibcode: 2012ApJ...744...85M

van der Wel, Arjen; Zirm, Andrew W.; Wuyts, Stijn +2 more

Using a mass-selected (M _sstarf >= 10¹¹ M _⊙) sample of 198 galaxies at 0 <= z <= 3.0 with Hubble Space Telescope/NICMOS H ₁₆₀-band images from the COSMOS survey, we find evidence for the evolution of the pair fraction above z ~ 2, an epoch in which massive galaxies are believed to undergo signif…

2012 • The Astrophysical Journal

eHST 89

The Contribution of TP-AGB and RHeB Stars to the Near-IR Luminosity of Local Galaxies: Implications for Stellar Mass Measurements of High-redshift Galaxies

DOI: 10.1088/0004-637X/748/1/47 Bibcode: 2012ApJ...748...47M

Williams, Benjamin F.; Boyer, Martha L.; Girardi, Léo +9 more

Using high spatial resolution Hubble Space Telescope WFC3 and Advanced Camera for Surveys imaging of resolved stellar populations, we constrain the contribution of thermally pulsing asymptotic giant branch (TP-AGB) stars and red helium burning (RHeB) stars to the 1.6 µm near-infrared (NIR) luminosities of 23 nearby galaxies, including dwarfs…

2012 • The Astrophysical Journal

eHST 89

A Study of the Dark Core in A520 with the Hubble Space Telescope: The Mystery Deepens

DOI: 10.1088/0004-637X/747/2/96 Bibcode: 2012ApJ...747...96J

Dalcanton, J. J.; Capak, P.; Hoekstra, H. +4 more

We present a Hubble Space Telescope/Wide Field Planetary Camera 2 weak-lensing study of A520, where a previous analysis of ground-based data suggested the presence of a dark mass concentration. We map the complex mass structure in much greater detail, leveraging more than a factor of three increase in the number density of source galaxies availabl…

2012 • The Astrophysical Journal

eHST 89

Dark gas in the solar neighborhood from extinction data

DOI: 10.1051/0004-6361/201118740 Bibcode: 2012A&A...543A.103P

Bernard, J. -P.; Fukui, Y.; Onishi, T. +4 more

Context. When modeling infrared or γ-ray data as a linear combination of observed gas tracers, excess emission has been detected compared to expectations from known neutral and molecular gas traced by HI and CO measurements, respectively. This excess might correspond to additional gas component. This so-called “dark gas” (DG) has been observed in …

2012 • Astronomy and Astrophysics

Planck 89

Hubble Space Telescope Measures of Mass Accretion Rates in the Orion Nebula Cluster

DOI: 10.1088/0004-637X/755/2/154 Bibcode: 2012ApJ...755..154M

Lodato, G.; Robberto, M.; Da Rio, N. +4 more

The present observational understanding of the evolution of the mass accretion rates (\dot{M}_acc) in pre-main-sequence stars is limited by the lack of accurate measurements of \dot{M}_acc over homogeneous and large statistical samples of young stars. Such observational effort is needed to properly constrain the theory of star formation and disk e…

2012 • The Astrophysical Journal

eHST 89