Search Publications

Near-infra-red spectroscopic ages of massive star clusters in M 82
DOI: 10.1051/0004-6361:200809439 Bibcode: 2008A&A...486..165L

Smith, L. J.; Gallagher, J. S., III; Mouhcine, M. +3 more

Context: Like other starburst galaxies, M 82 hosts compact, massive (>5 × 105 M) young star clusters that are interesting both in their own right and as benchmarks for population synthesis models.
Aims: In addition to assessing or reassessing the properties of some of the brightest near-IR sources in M 82, this paper …

2008 Astronomy and Astrophysics
eHST 28
Signature of mass supply to quiet coronal loops
DOI: 10.1051/0004-6361:20078813 Bibcode: 2008A&A...478..915T

Tu, C. -Y.; Marsch, E.; Tian, H. +2 more

Aims:The physical implication of large blue shift of Ne viii in the quiet Sun region is investigated in this paper.
Methods: We compare the significant Ne viii blue shifts, which are visible as large blue patches on the Doppler-shift map of a middle-latitude quiet-Sun region observed by SUMER, with the coronal magnetic-field structures as reco…

2008 Astronomy and Astrophysics
SOHO 28
A nanoflare model for active region radiance: application of artificial neural networks
DOI: 10.1051/0004-6361:200810911 Bibcode: 2008A&A...492L..13B

Solanki, S. K.; Innes, D. E.; Safari, H. +2 more

Context: Nanoflares are small impulsive bursts of energy that blend with and possibly make up much of the solar background emission. Determining their frequency and energy input is central to understanding the heating of the solar corona. One method is to extrapolate the energy frequency distribution of larger individually observed flares to lower…

2008 Astronomy and Astrophysics
SOHO 27
Neon and oxygen in low activity stars: towards a coronal unification with the Sun
DOI: 10.1051/0004-6361:200809690 Bibcode: 2008A&A...486..995R

Schmitt, J. H. M. M.; Robrade, J.; Favata, F.

Aims: The disagreement between helioseismology and a recent downward revision of solar abundances has resulted in a controversy about the true neon abundance of the Sun and other stars. We study the coronal Ne/O abundance ratios of nearby stars with modest activity levels and investigate a possible peculiarity of the Sun among the stellar populati…

2008 Astronomy and Astrophysics
XMM-Newton 27
The red and blue galaxy populations in the GOODS field: evidence for an excess of red dwarfs
DOI: 10.1051/0004-6361:20077959 Bibcode: 2008A&A...477..763S

Castellano, M.; Pentericci, L.; Fontana, A. +8 more

Aims: We study the evolution of the galaxy population up to z∼ 3 as a function of its colour properties. In particular, luminosity functions and luminosity densities were derived as a function of redshift for the blue/late and red/early populations.
Methods: We use data from the GOODS-MUSIC catalogue, which have typical magnitude limits z

2008 Astronomy and Astrophysics
eHST 27
Extremely massive young clusters in NGC 1365
DOI: 10.1051/0004-6361:20077621 Bibcode: 2008A&A...492....3G

Pantin, E.; Panuzzo, P.; Alloin, D. +5 more

Context: In a previous work, three bright mid-infrared/radio sources were discovered in the nuclear region of starburst/AGN galaxy NGC 1365.
Aims: The present study aims to confirm that these sources are indeed young and massive “embedded” clusters, and derive their physical parameters, such as extinction, age and mass.
Methods: Using ISAA…

2008 Astronomy and Astrophysics
eHST 26
CME liftoff with high-frequency fragmented type II burst emission
DOI: 10.1051/0004-6361:200810049 Bibcode: 2008A&A...490..357P

Vainio, R.; Pomoell, J.; Pohjolainen, S.

Aims: Solar radio type II bursts are rarely seen at frequencies higher than a few hundred MHz. Since metric type II bursts are thought to be signatures of propagating shock waves, it is of interest to know how these shocks, and the type II bursts, are formed. In particular, how are high-frequency, fragmented type II bursts created? Are there diffe…

2008 Astronomy and Astrophysics
SOHO 26
Abundances of planetary nebula NGC 2392
DOI: 10.1051/0004-6361:20079041 Bibcode: 2008A&A...481..393P

Pottasch, S. R.; Bernard-Salas, J.; Roellig, T. L.

The spectra of the planetary nebula NGC 2392 is reanalysed using spectral measurements made in the mid-infrared with the Spitzer Space Telescope. The aim is to determine the chemical composition of this object. We also make use of IUE and ground based spectra. Abundances determined from the mid-infrared lines, which are insensit…

2008 Astronomy and Astrophysics
IUE 26
Infrared to X-ray observations of PKS 2155-304 in a low state
DOI: 10.1051/0004-6361:200809973 Bibcode: 2008A&A...484L..35F

Maraschi, L.; Covino, S.; Tagliaferri, G. +14 more

Aims: Our goal is to understand the nature of blazars and the mechanisms for the generation of high-energy γ-rays, through the investigation of the prototypical blazar PKS 2155{-}304, which shows complex behaviour.
Methods: We analyze simultaneous infrared-to-X-ray observations obtained with XMM-Newton and REM on November 7, 2006, when the sou…

2008 Astronomy and Astrophysics
XMM-Newton 26
Star cluster versus field star formation in the nucleus of the prototype starburst galaxy M 82
DOI: 10.1051/0004-6361:200809653 Bibcode: 2008A&A...484..711B

de Grijs, R.; Cerviño, M.; Barker, S.

We analyse high-resolution Hubble Space Telescope/Advanced Camera for Surveys imaging of the nuclear starburst region of M 82, obtained as part of the Hubble Heritage mosaic made of this galaxy, in four filters (Johnson-Cousins equivalent B, V, and I broad bands, and an Hα narrow-band filter), as well as subsequently acquired U-band images. We fin…

2008 Astronomy and Astrophysics
eHST 26