Search Publications

Benchmarking atomic data for the CHIANTI atomic database: coronal lines observed by Hinode EIS
DOI: 10.1051/0004-6361/201117592 Bibcode: 2012A&A...537A..38D

Del Zanna, G.

The coronal lines that are observable in the Hinode EUV Imaging Spectrometer (EIS) wavelengths are assessed with new atomic data that have recently become available for a range of important ions. EIS spectral lines are identified based on their spatial variation across different solar regions, their wavelengths, and their intensities. Two off-limb…

2012 Astronomy and Astrophysics
Hinode 65
A Brightest Cluster Galaxy with an Extremely Large Flat Core
DOI: 10.1088/0004-637X/756/2/159 Bibcode: 2012ApJ...756..159P

Donahue, Megan; Broadhurst, Tom; Moustakas, John +14 more

Hubble Space Telescope images of the galaxy cluster A2261, obtained as part of the Cluster Lensing And Supernova survey with Hubble, show that the brightest galaxy in the cluster, A2261-BCG, has the largest core yet detected in any galaxy. The cusp radius of A2261-BCG is 3.2 kpc, twice as big as the next largest core known, and ~3 × bigger than th…

2012 The Astrophysical Journal
eHST 65
Herschel/HIFI observations of O-rich AGB stars: molecular inventory
DOI: 10.1051/0004-6361/201117524 Bibcode: 2012A&A...537A.144J

Menten, K. M.; Olofsson, H.; Marston, A. P. +17 more


Aims: Spectra, taken with the heterodyne instrument, HIFI, aboard the Herschel Space Observatory, of O-rich asymptotic giant branch (AGB) stars which form part of the guaranteed time key program HIFISTARS are presented. The aim of this program is to study the dynamical structure, mass-loss driving mechanism, and chemistry of the outflows from…

2012 Astronomy and Astrophysics
Herschel 65
A Reverberation Lag for the High-ionization Component of the Broad-line Region in the Narrow-line Seyfert 1 Mrk 335
DOI: 10.1088/2041-8205/744/1/L4 Bibcode: 2012ApJ...744L...4G

Skowron, J.; Kochanek, C. S.; Horne, Keith +37 more

We present the first results from a detailed analysis of photometric and spectrophotometric data on the narrow-line Seyfert 1 (NLS1) galaxy Mrk 335, collected over a 120 day span in the fall of 2010. From these data we measure the lag in the He II λ4686 broad emission line relative to the optical continuum to be 2.7 ± 0.6 days and the lag in the H…

2012 The Astrophysical Journal
eHST 65
The star formation history and dust content in the far outer disc of M31
DOI: 10.1111/j.1365-2966.2011.20234.x Bibcode: 2012MNRAS.420.2625B

Lewis, Geraint F.; McConnachie, Alan W.; Ibata, Rodrigo A. +7 more

We present a detailed analysis of two fields located 26 kpc (∼5 radial scalelengths) from the centre of M31 along the south-west semimajor axis of the disc. One field samples the major axis populations - the Outer Disc field - while the other is offset by ∼18 arcmin and samples the warp in the stellar disc - the warp field. The colour-magnitude di…

2012 Monthly Notices of the Royal Astronomical Society
eHST 65
A quantitative study of O stars in NGC 2244 and the Monoceros OB2 association
DOI: 10.1051/0004-6361/201117458 Bibcode: 2012A&A...538A..39M

Martins, F.; Hillier, D. J.; Rauw, G. +1 more


Aims: Our goal is to determine the stellar and wind properties of seven O stars in the cluster NGC 2244 and three O stars in the OB association Mon OB2. These properties give us insight into the mass loss rates of O stars. They allow us to both check the validity of rotational mixing in massive stars and to better understand the effects of th…

2012 Astronomy and Astrophysics
IUE 65
The Progenitor of the Type Ia Supernova that Created SNR 0519-69.0 in the Large Magellanic Cloud
DOI: 10.1088/2041-8205/747/2/L19 Bibcode: 2012ApJ...747L..19E

Schaefer, Bradley E.; Pagnotta, Ashley; Edwards, Zachary I.

Models for the progenitor systems of Type Ia supernovae can be divided into double-degenerate systems, which contain two white dwarfs, and single-degenerate systems, which contain one white dwarf plus one companion star (either a red giant, a subgiant, or a >1.16 M main-sequence star). The white dwarf is destroyed in the supernova …

2012 The Astrophysical Journal
eHST 65
The evolution of the star formation activity per halo mass up to redshift ~1.6 as seen by Herschel
DOI: 10.1051/0004-6361/201117973 Bibcode: 2012A&A...537A..58P

Finoguenov, A.; Berta, S.; Magnelli, B. +40 more


Aims: Star formation in massive galaxies is quenched at some point during hierarchical mass assembly. To understand where and when the quenching processes takes place, we study the evolution of the total star formation rate per unit total halo mass (Σ(SFR)/M) in three different mass scales: low mass halos (field galaxies), groups, and cluster…

2012 Astronomy and Astrophysics
Herschel 64
Measuring the Abundance of Sub-kilometer-sized Kuiper Belt Objects Using Stellar Occultations
DOI: 10.1088/0004-637X/761/2/150 Bibcode: 2012ApJ...761..150S

Livio, Mario; Nelan, Edmund P.; Gal-Yam, Avishay +6 more

We present here the analysis of about 19,500 new star hours of low ecliptic latitude observations (|b| <= 20°) obtained by the Hubble Space Telescope's Fine Guidance Sensors over a time span of more than nine years, which is in addition to the ~12, 000 star hours previously analyzed by Schlichting et al. Our search for stellar occultations by s…

2012 The Astrophysical Journal
eHST 64
Systematic Investigation of Solar Modulation of Galactic Protons for Solar Cycle 23 Using a Monte Carlo Approach with Particle Drift Effects and Latitudinal Dependence
DOI: 10.1088/0004-637X/745/2/132 Bibcode: 2012ApJ...745..132B

Boella, G.; Gervasi, M.; Grandi, D. +8 more

A propagation model of galactic cosmic protons through the heliosphere was implemented using a two-dimensional Monte Carlo approach to determine the differential intensities of protons during solar cycle 23. The model includes the effects due to the variation of solar activity during the propagation of cosmic rays from the boundary of the heliopau…

2012 The Astrophysical Journal
Ulysses 64