Search Publications
The galaxy major merger fraction to {z} 1
Pérez-González, P. G.; López-Sanjuan, C.; Gallego, J. +4 more
Aims: The importance of disc-disc major mergers in galaxy evolution remains uncertain. We study the major merger fraction in a SPITZER/IRAC-selected catalogue in the GOODS-S field up to z 1 for luminosity- and mass-limited samples.
Methods: We select disc-disc merger remnants on the basis of morphological asymmetries/distortions, and address t…
The solar chromosphere at high resolution with IBIS. II. Acoustic shocks in the quiet internetwork and the role of magnetic fields
Vecchio, A.; Cauzzi, G.; Reardon, K. P.
Context: The exact nature of the quiet solar chromosphere and especially its temporal variation, are still subjects of intense debate. One of the contentious issues is the possible role of the magnetic field in structuring the quieter solar regions.
Aims: We characterize the dynamics of the quiet inter-network chromosphere by studying the occu…
X-ray evidence for a mildly relativistic and variable outflow in the luminous Seyfert 1 galaxy Mrk 509
Maraschi, L.; Bianchi, S.; Cappi, M. +9 more
Context: There is growing evidence for the presence of blueshifted Fe K absorption lines in a number of radio-quiet AGNs and QSOs. These may be fundamental to probe flow dynamics near supermassive black holes.
Aims: Here we aim to verify and better characterise the existence of such Fe K absorption at ~8-10 keV in the luminous Seyfert 1 galaxy…
The zCOSMOS survey: the role of the environment in the evolution of the luminosity function of different galaxy types
Kneib, J. -P.; Maccagni, D.; Aussel, H. +64 more
Aims. An unbiased and detailed characterization of the galaxy luminosity function (LF) is a basic requirement in many astrophysical issues: it is of particular interest in assessing the role of the environment in the evolution of the LF of different galaxy types.
Methods: We studied the evolution in the B band LF to redshift z∼ 1 in the zCOSM…
Empirical estimate of Lyα escape fraction in a statistical sample of Lyα emitters
Schaerer, D.; Östlin, G.; Hayes, M. +4 more
Context: The Lyman-alpha (Lyα) recombination line is a fundamental tool for galaxy evolution studies and modern observational cosmology. However, subsequent interpretations are still prone to a number of uncertainties. Besides numerical efforts, empirical data are urgently needed for a better understanding of the Lyα escape process.
Aims: We e…
A cool starspot or a second transiting planet in the TrES-1 system?
Alonso, R.; Deeg, H. J.; Brown, T. M. +6 more
Aims: We investigate the origin of a flux increase found during a transit of TrES-1, observed with the HST (Hubble Space Telescope). This feature in the HST light curve cannot be attributed to noise and is supposedly a dark area on the stellar surface of the host star eclipsed by TrES-1 during its transit. We investigate the likelihood of two poss…
The size-density relation of extragalactic H II regions
Hunt, L. K.; Hirashita, H.
Aims: We investigate the size-density relation in extragalactic H ii regions, with the aim of understanding the role of dust and different physical conditions in the ionized medium.
Methods: First, we compiled several observational data sets for Galactic and extragalactic H ii regions and confirm that extragalactic H ii regions follow the same…
Quiet Sun mini-coronal mass ejections activated by supergranular flows
Innes, D. E.; Potts, H. E.; Attie, R. +1 more
Context: The atmosphere of the quiet Sun is controlled by photospheric flows sweeping up concentrations of mixed polarity magnetic field. Along supergranule boundaries and junctions, there is a strong correlation between magnetic flux and bright chromospheric and transition region emission.
Aims: The aim is to investigate the relationship betw…
A joint spectro-imaging analysis of the XMM-Newton and HESS observations of the supernova remnant RX J1713.7-3946
Ballet, J.; Lemoine-Goumard, M.; Decourchelle, A. +5 more
Context: The supernova remnant (SNR) RX J1713.7-3946 (also known as G347.3-0.5) is part of the class of remnants dominated by synchrotron emission in X-rays. It is also one of the few shell-type SNRs observed at TeV energies allowing us to investigate particle acceleration at SNRs shock.
Aims: Our goal is to compare spatial and spectral proper…
XMM-Newton observations of Seyfert galaxies from the Palomar spectroscopic survey: the X-ray absorption distribution
Georgantopoulos, I.; Akylas, A.
We present XMM-Newton spectral analysis of all 38 Seyfert galaxies from the Palomar spectroscopic sample of galaxies. These are found at distances of up to 67 Mpc and cover the absorbed 2-10 keV luminosity range ~1038-1043 erg s-1. Our aim is to determine the distribution of the X-ray absorption in the local Univer…