Search Publications

Pitch angle distribution of suprathermal electrons behind dipolarization fronts: A statistical overview
DOI: 10.1029/2012JA018141 Bibcode: 2012JGRA..11712221F

Daly, P. W.; André, M.; Vaivads, A. +5 more

We examine the pitch angle distribution (PAD) of suprathermal electrons (>40 keV) inside the flux pileup regions (FPRs) that are located behind the dipolarization fronts (DFs), in order to better understand the particle energization mechanisms operating therein. The 303 earthward-propagating DFs observed during 9 years (2001-2009) by Cluster 1 …

2012 Journal of Geophysical Research (Space Physics)
Cluster 148
Herschel/PACS spectroscopy of NGC 4418 and Arp 220: H2O, H218O, OH, 18OH, O I, HCN, and NH3
DOI: 10.1051/0004-6361/201118029 Bibcode: 2012A&A...541A...4G

Lutz, D.; Genzel, R.; Poglitsch, A. +14 more

Full range Herschel/PACS spectroscopy of the (ultra)luminous infrared galaxies NGC 4418 and Arp 220, observed as part of the SHINING key programme, reveals high excitation in H2O, OH, HCN, and NH3. In NGC 4418, absorption lines were detected with Elower > 800 K (H2O), 600 K (OH), 1075 K (HCN), and 600…

2012 Astronomy and Astrophysics
Herschel 148
The Herschel Exploitation of Local Galaxy Andromeda (HELGA). II. Dust and Gas in Andromeda
DOI: 10.1088/0004-637X/756/1/40 Bibcode: 2012ApJ...756...40S

Blommaert, J. A. D. L.; Clements, D. L.; Boquien, M. +27 more

We present an analysis of the dust and gas in Andromeda, using Herschel images sampling the entire far-infrared peak. We fit a modified-blackbody model to ~4000 quasi-independent pixels with spatial resolution of ~140 pc and find that a variable dust-emissivity index (β) is required to fit the data. We find no significant long-wavelength excess ab…

2012 The Astrophysical Journal
Herschel 148
Cosmic Microwave Background Constraints on the Duration and Timing of Reionization from the South Pole Telescope
DOI: 10.1088/0004-637X/756/1/65 Bibcode: 2012ApJ...756...65Z

Doré, O.; Bleem, L. E.; Stark, A. A. +48 more

The epoch of reionization is a milestone of cosmological structure formation, marking the birth of the first objects massive enough to yield large numbers of ionizing photons. However, the mechanism and timescale of reionization remain largely unknown. Measurements of the cosmic microwave background (CMB) Doppler effect from ionizing bubbles embed…

2012 The Astrophysical Journal
Planck 148
Extreme AGN feedback in the MAssive Cluster Survey: a detailed study of X-ray cavities at z>0.3
DOI: 10.1111/j.1365-2966.2011.20405.x Bibcode: 2012MNRAS.421.1360H

Fabian, A. C.; Hlavacek-Larrondo, J.; Edge, A. C. +4 more

We present the first statistical study of X-ray cavities in distant clusters of galaxies (z > 0.3). With the aim of providing further insight into how active galactic nucleus (AGN) feedback operates at higher redshift, we have analysed the Chandra X-ray observations of the MAssive Cluster Survey (MACS) and searched for surface brightness depres…

2012 Monthly Notices of the Royal Astronomical Society
eHST 147
The CFHTLS-Strong Lensing Legacy Survey (SL2S): Investigating the Group-scale Lenses with the SARCS Sample
DOI: 10.1088/0004-637X/749/1/38 Bibcode: 2012ApJ...749...38M

Kneib, J. -P.; Alard, C.; Gavazzi, R. +5 more

We present the Strong Lensing Legacy Survey-ARCS (SARCS) sample compiled from the final T0006 data release of the Canada-France-Hawaii Telescope Legacy Survey (CFHTLS) covering a total non-overlapping area of 159 deg2. We adopt a semi-automatic method to find gravitational arcs in the survey that makes use of an arc-finding algorithm. T…

2012 The Astrophysical Journal
eHST 147
Properties of Galactic early-type O-supergiants. A combined FUV-UV and optical analysis
DOI: 10.1051/0004-6361/201118594 Bibcode: 2012A&A...544A..67B

Bouret, J. -C.; Hillier, D. J.; Fullerton, A. W. +1 more


Aims: We aim to constrain the properties and evolutionary status of early and mid-spectral type supergiants (from O4 to O7.5). These posses the highest mass-loss rates among the O stars, and exhibit conspicuous wind profiles.
Methods: Using the non-LTE wind code cmfgen we simultaneously analyzed the FUV-UV and optical spectral range to d…

2012 Astronomy and Astrophysics
IUE 147
The Star Formation Rate Function for Redshift z ~ 4-7 Galaxies: Evidence for a Uniform Buildup of Star-forming Galaxies during the First 3 Gyr of Cosmic Time
DOI: 10.1088/0004-637X/756/1/14 Bibcode: 2012ApJ...756...14S

van Dokkum, Pieter G.; Franx, Marijn; Illingworth, Garth D. +4 more

We combine recent estimates of dust extinction at z ~ 4-7 with UV luminosity function (LF) determinations to derive star formation rate (SFR) functions at z ~ 4-7. SFR functions provide a more physical description of galaxy buildup at high redshift and allow for direct comparisons to SFRs at lower redshifts determined by a variety of techniques. O…

2012 The Astrophysical Journal
eHST 147
HST-COS Observations of AGNs. I. Ultraviolet Composite Spectra of the Ionizing Continuum and Emission Lines
DOI: 10.1088/0004-637X/752/2/162 Bibcode: 2012ApJ...752..162S

Shull, J. Michael; Danforth, Charles W.; Stevans, Matthew

The ionizing fluxes from quasars and other active galactic nuclei (AGNs) are critical for interpreting the emission-line spectra of AGNs and for photoionization and heating of the intergalactic medium. Using ultraviolet spectra from the Cosmic Origins Spectrograph (COS) on the Hubble Space Telescope (HST), we have directly measured the rest-frame …

2012 The Astrophysical Journal
IUE eHST 146
The Nature of Double-peaked [O III] Active Galactic Nuclei
DOI: 10.1088/0004-637X/745/1/67 Bibcode: 2012ApJ...745...67F

Djorgovski, S. G.; Myers, Adam D.; Aldering, G. +4 more

Active galactic nuclei (AGNs) with double-peaked [O III] lines are suspected to be sub-kpc or kpc-scale binary AGNs. However, pure gas kinematics can produce the same double-peaked line profile in spatially integrated spectra. Here we combine integral-field spectroscopy and high-resolution imaging of 42 double-peaked [O III] AGNs from the Sloan Di…

2012 The Astrophysical Journal
eHST 143