Search Publications

The Chandra View of NGC 4178: The Lowest Mass Black Hole in a Bulgeless Disk Galaxy?
DOI: 10.1088/0004-637X/753/1/38 Bibcode: 2012ApJ...753...38S

Cheung, C. C.; Böker, T.; Secrest, N. J. +3 more

Using high-resolution Chandra data, we report the presence of a weak X-ray point source coincident with the nucleus of NGC 4178, a late-type bulgeless disk galaxy known to have high-ionization mid-infrared (mid-IR) lines typically associated with active galactic nuclei (AGNs). Although the faintness of this source precludes a direct spectral analy…

2012 The Astrophysical Journal
eHST 42
Unusual quasars from the Sloan Digital Sky Survey selected by means of Kohonen self-organising maps
DOI: 10.1051/0004-6361/201118143 Bibcode: 2012A&A...541A..77M

Meusinger, H.; Scholz, R. -D.; de Hoon, A. +4 more

Context. Large spectroscopic surveys have discovered very peculiar and hitherto unknown types of active galactic nuclei (AGN). Such rare objects may hold clues to the accretion history of the supermassive black holes at the centres of galaxies.
Aims: We aim to create a sizeable sample of unusual quasars from the unprecedented spectroscopic da…

2012 Astronomy and Astrophysics
eHST 42
Evidence for a Wide Range of Ultraviolet Obscuration in z ~ 2 Dusty Galaxies from the GOODS-Herschel Survey
DOI: 10.1088/0004-637X/759/1/28 Bibcode: 2012ApJ...759...28P

Dickinson, Mark; Daddi, Emanuele; Dey, Arjun +20 more

Dusty galaxies at z ~ 2 span a wide range of relative brightness between rest-frame mid-infrared (8 µm) and ultraviolet wavelengths. We attempt to determine the physical mechanism responsible for this diversity. Dust-obscured galaxies (DOGs), which have rest-frame mid-IR to UV flux density ratios >~ 1000, might be abnormally bright in the…

2012 The Astrophysical Journal
Herschel 42
Fe K emission from active galaxies in the COSMOS field
DOI: 10.1051/0004-6361/201118203 Bibcode: 2012A&A...537A..86I

Sanders, D. B.; Taniguchi, Y.; Salvato, M. +14 more

We present a rest-frame spectral stacking analysis of ~1000 X-ray sources detected in the XMM-COSMOS field to investigate the iron-K line properties of active galaxies beyond redshift z ~ 1. In Type I AGN that have a typical X-ray luminosity of LX ~ 1.5 × 1044 (erg s-1) and z ~ 1.6 the cold Fe K at 6.4 keV is weak …

2012 Astronomy and Astrophysics
XMM-Newton 42
Aphelion water-ice cloud mapping and property retrieval using the OMEGA imaging spectrometer onboard Mars Express
DOI: 10.1029/2011JE003940 Bibcode: 2012JGRE..117.0J07M

Bibring, J. -P.; Gondet, B.; Langevin, Y. +8 more

Mapping of the aphelion clouds over the Tharsis plateau and retrieval of their particle size and visible opacity are made possible by the OMEGA imaging spectrometer aboard Mars Express. Observations cover the period from MY26 Ls = 330° to MY29 Ls = 180° and are acquired at various local times, ranging from 8 AM to 6 PM. Cloud…

2012 Journal of Geophysical Research (Planets)
MEx 42
PAndromeda—First Results from the High-cadence Monitoring of M31 with Pan-STARRS 1
DOI: 10.1088/0004-6256/143/4/89 Bibcode: 2012AJ....143...89L

Price, P. A.; Saglia, R. P.; Chambers, K. C. +19 more

The Pan-STARRS 1 (PS1) survey of M31 (PAndromeda) is designed to identify gravitational microlensing events, caused by bulge and disk stars (self-lensing) and by compact matter in the halos of M31 and the Milky Way (halo lensing or lensing by massive compact halo objects). With the 7 deg2 field of view (FOV) of PS1, the entire disk of M…

2012 The Astronomical Journal
eHST 42
Valleys, paleolakes and possible shorelines at the Libya Montes/Isidis boundary: Implications for the hydrologic evolution of Mars
DOI: 10.1016/j.icarus.2012.03.012 Bibcode: 2012Icar..219..393E

Poulet, F.; Jaumann, R.; Hiesinger, H. +5 more

We describe the results of our morphologic, stratigraphic and mineralogic investigations of fluvial landforms, paleolakes and possible shoreline morphologies at the Libya Montes/Isidis Planitia boundary. The landforms are indicative of aqueous activity and standing bodies of water, including lakes, seas and oceans, that are attributed to a complex…

2012 Icarus
MEx 42
AKARI near-infrared spectroscopy of the aromatic and aliphatic hydrocarbon emission features in the galactic superwind of M 82
DOI: 10.1051/0004-6361/201218904 Bibcode: 2012A&A...541A..10Y

Onaka, T.; Kaneda, H.; Minh, Y. C. +4 more


Aims: We investigate the properties of hydrocarbon grains in the galactic superwind of M 82.
Methods: With AKARI, we performed near-infrared (2.5-4.5 µm) spectroscopic observations of 34 regions in M 82 including its northern and southern halos.
Results: Many of the spectra show strong emission at 3.3 µm caused by polycy…

2012 Astronomy and Astrophysics
AKARI 42
I Zw 18 as morphological paradigm for rapidly assembling high-z galaxies
DOI: 10.1051/0004-6361/201117551 Bibcode: 2012A&A...537A.126P

Östlin, G.; Papaderos, P.

Context.I Zw 18, ever since regarded as the prototypical blue compact dwarf (BCD) galaxy, is, quite ironically, the most atypical BCD known. This is because its large low-surface brightness (LSB) envelope is not due to an old underlying stellar host, as invariably is the case for typical BCDs, but is entirely due to extended neb…

2012 Astronomy and Astrophysics
eHST 42
"TNOs are Cool": A survey of the trans-Neptunian region. VII. Size and surface characteristics of (90377) Sedna and 2010 EK139
DOI: 10.1051/0004-6361/201218874 Bibcode: 2012A&A...541L...6P

Hartogh, P.; Pál, A.; Lellouch, E. +14 more

We present estimates of the basic physical properties (size and albedo) of (90377) Sedna, a prominent member of the detached trans-Neptunian object population and the recently discovered scattered disk object 2010 EK139, based on the recent observations acquired with the Herschel Space Observatory, within the "TNOs are Cool!" key progra…

2012 Astronomy and Astrophysics
Herschel 42