Search Publications

On the Nature and Genesis of EUV Waves: A Synthesis of Observations from SOHO, STEREO, SDO, and Hinode (Invited Review)
DOI: 10.1007/s11207-012-9988-6 Bibcode: 2012SoPh..281..187P

Vourlidas, Angelos; Patsourakos, Spiros

A major, albeit serendipitous, discovery of the SOlar and Heliospheric Observatory mission was the observation by the Extreme Ultraviolet Telescope (EIT) of large-scale extreme ultraviolet (EUV) intensity fronts propagating over a significant fraction of the Sun's surface. These so-called EIT or EUV waves are associated with eruptive phenomena and…

2012 Solar Physics
Hinode SOHO 139
The dominant role of mergers in the size evolution of massive early-type galaxies since z ~ 1
DOI: 10.1051/0004-6361/201219085 Bibcode: 2012A&A...548A...7L

Kneib, J. -P.; Aussel, H.; Cimatti, A. +60 more


Aims: The role of galaxy mergers in massive galaxy evolution, and in particular to mass assembly and size growth, remains an open question. In this paper we measure the merger fraction and rate, both minor and major, of massive early-type galaxies (M ≥ 1011 M) in the COSMOS field, and study their role in m…

2012 Astronomy and Astrophysics
eHST 138
The Galaxy Zoo survey for giant AGN-ionized clouds: past and present black hole accretion events
DOI: 10.1111/j.1365-2966.2011.20101.x Bibcode: 2012MNRAS.420..878K

Schawinski, Kevin; Sonnenfeld, Alessandro; Keel, William C. +8 more

Some active galactic nuclei (AGN) are surrounded by extended emission-line regions (EELRs), which trace both the illumination pattern of escaping radiation and its history over the light travel time from the AGN to the gas. From a new set of such EELRs, we present evidence that the AGN in many Seyfert galaxies undergo luminous episodes 0.2-2 ? yea…

2012 Monthly Notices of the Royal Astronomical Society
AKARI 137
Observations of Herbig Ae/Be stars with Herschel/PACS. The atomic and molecular contents of their protoplanetary discs
DOI: 10.1051/0004-6361/201219225 Bibcode: 2012A&A...544A..78M

Pinte, C.; Ménard, F.; Dent, W. R. F. +15 more

We observed a sample of 20 representative Herbig Ae/Be stars and 5 A-type debris discs with PACS onboard Herschel, as part of the GAS in Protoplanetary Systems (GASPS) project. The observations were done in spectroscopic mode, and cover the far-infrared lines of [O i], [C ii], CO, CH+, H2O, and OH. We have a [O i] 63 µm…

2012 Astronomy and Astrophysics
Herschel 137
Dust temperature and CO → H2 conversion factor variations in the SFR-M plane
DOI: 10.1051/0004-6361/201220074 Bibcode: 2012A&A...548A..22M

Berta, S.; Magnelli, B.; Nordon, R. +15 more

Deep Herschel PACS/SPIRE imaging and 12CO(2-1) line luminosities from the IRAM Plateau de Bure Interferometer are combined for a sample of 17 galaxies at z > 1 from the GOODS-N field. The sample includes galaxies both on and above the main sequence (MS) traced by star-forming galaxies in the SFR-M plane. The far-infrared …

2012 Astronomy and Astrophysics
Herschel eHST 137
How Do Star-forming Galaxies at z > 3 Assemble Their Masses?
DOI: 10.1088/0004-637X/752/1/66 Bibcode: 2012ApJ...752...66L

Papovich, Casey; Ferguson, Henry C.; Giavalisco, Mauro +8 more

We investigate how star-forming galaxies typically assemble their masses at high redshift. Taking advantage of the deep multi-wavelength coverage of the GOODS data set, we select two of the largest samples of high-redshift star-forming galaxies based on their UV colors and measure stellar mass of individual galaxies. We use template-fitting photom…

2012 The Astrophysical Journal
eHST 137
CLASH: Precise New Constraints on the Mass Profile of the Galaxy Cluster A2261
DOI: 10.1088/0004-637X/757/1/22 Bibcode: 2012ApJ...757...22C

Donahue, Megan; Broadhurst, Tom; Maoz, Dan +43 more

We precisely constrain the inner mass profile of A2261 (z = 0.225) for the first time and determine that this cluster is not "overconcentrated" as found previously, implying a formation time in agreement with ΛCDM expectations. These results are based on multiple strong-lensing analyses of new 16-band Hubble Space Telescope imaging obtained as par…

2012 The Astrophysical Journal
eHST 136
Solar Magnetic Field Reversals and the Role of Dynamo Families
DOI: 10.1088/0004-637X/757/1/96 Bibcode: 2012ApJ...757...96D

Hoeksema, J. T.; Brun, A. S.; DeRosa, M. L.

The variable magnetic field of the solar photosphere exhibits periodic reversals as a result of dynamo activity occurring within the solar interior. We decompose the surface field as observed by both the Wilcox Solar Observatory and the Michelson Doppler Imager into its harmonic constituents, and present the time evolution of the mode coefficients…

2012 The Astrophysical Journal
SOHO 136
Heavily obscured quasar host galaxies at z ∼ 2 are discs, not major mergers
DOI: 10.1111/j.1745-3933.2012.01302.x Bibcode: 2012MNRAS.425L..61S

Schawinski, Kevin; Urry, C. Megan; Simmons, Brooke D. +2 more

We explore the nature of heavily obscured quasar host galaxies at z∼ 2 using deep Hubble Space Telescope Wide Field Camera 3/infrared imaging of 28 dust-obscured galaxies (DOGs) to investigate the role of major mergers in driving black hole growth. The high levels of obscuration of the quasars selected for this study act as a natural coronagraph, …

2012 Monthly Notices of the Royal Astronomical Society
eHST 135
An overfilled lacustrine system and progradational delta in Jezero crater, Mars: Implications for Noachian climate
DOI: 10.1016/j.pss.2012.02.003 Bibcode: 2012P&SS...67...28S

Head, James W.; Fassett, Caleb I.; Schon, Samuel C.

The presence of valley networks and open-basin lakes in the late Noachian is cited as evidence for overland flow of liquid water and thus a climate on early Mars that might have supported precipitation and runoff. Outstanding questions center on the nature of such a climate, its duration and variability, and its cause. Open basin lakes, their inte…

2012 Planetary and Space Science
MEx 135