Search Publications
XRF 100316D/SN 2010bh and the Nature of Gamma-Ray Burst Supernovae
D'Avanzo, P.; Melandri, A.; Pian, E. +21 more
We present ground-based and Hubble Space Telescope optical and infrared observations of Swift XRF 100316D/SN 2010bh. It is seen that the optical light curves of SN 2010bh evolve at a faster rate than the archetype gamma-ray burst supernova (GRB-SN) 1998bw, but at a similar rate to SN 2006aj, an SN that was spectroscopically linked with XRF 060218,…
Hα emitters in z∼ 2 protoclusters: evidence for faster evolution in dense environments
Pentericci, L.; Röttgering, H. J. A.; Miley, G. K. +4 more
This is a study of Hα emitters in two dense galaxy protoclusters surrounding radio galaxies at z∼ 2. We show that the protocluster surrounding MRC 1138-262 contains 14 ± 2 times more Hα candidates than the average field (9σ significance), and the z= 2.35 radio galaxy 4C +10.48 is surrounded by 12 ± 2 times more emitters than the field (5σ), so it …
Planck early results. XV. Spectral energy distributions and radio continuum spectra of northern extragalactic radio sources
Kneissl, R.; Miville-Deschênes, M. -A.; Bernard, J. -P. +246 more
Spectral energy distributions (SEDs) and radio continuum spectra are presented for a northern sample of 104 extragalactic radio sources, based on the Planck Early Release Compact Source Catalogue (ERCSC) and simultaneous multifrequency data. The nine Planck frequencies, from 30 to 857 GHz, are complemented by a set of simultaneous observations ran…
SN 2009md: another faint supernova from a low-mass progenitor
Sollerman, J.; Gal-Yam, A.; Smartt, S. J. +21 more
We present adaptive optics imaging of the core-collapse supernova (SN) 2009md, which we use together with archival Hubble Space Telescope data to identify a coincident progenitor candidate. We find the progenitor to have an absolute magnitude of V=-4.63+0.3-0.4 mag and a colour of V-I= 2.29+0.25-0.39 mag…
The environments of short-duration gamma-ray bursts and implications for their progenitors
Berger, Edo
The study of short-duration gamma-ray bursts (GRBs) experienced a complete revolution in recent years thanks to the discovery of the first afterglows and host galaxies starting in May 2005. These observations demonstrated that short GRBs are cosmological in origin, reside in both star forming and elliptical galaxies, are not associated with supern…
Properties of Energetic Ions in the Solar Atmosphere from γ-Ray and Neutron Observations
Vilmer, N.; MacKinnon, A. L.; Hurford, G. J.
Gamma-rays and neutrons are the only sources of information on energetic ions present during solar flares and on properties of these ions when they interact in the solar atmosphere. The production of γ-rays and neutrons results from convolution of the nuclear cross-sections with the ion distribution functions in the atmosphere. The observed γ-ray …
Probing cluster formation under extreme conditions: massive star clusters in blue compact galaxies
Östlin, G.; Adamo, A.; Zackrisson, E.
The numerous and massive young star clusters in blue compact galaxies (BCGs) are used to investigate the properties of their hosts. We test whether BCGs follow claimed relations between cluster populations and their hosts, such as the fraction of the total luminosity contributed by the clusters as function of the mean star formation rate (SFR) den…
Triggering process of whistler mode chorus emissions in the magnetosphere
Omura, Yoshiharu; Nunn, David
Chorus emissions are triggered from the linear cyclotron instability driven by the temperature anisotropy of energetic electrons (10-100 keV) in the magnetosphere. Chorus emissions grow as an absolute nonlinear instability near the magnetic equator because of the presence of an electromagnetic electron hole in velocity space. The transition proces…
A SINFONI integral field spectroscopy survey for galaxy counterparts to damped Lyman α systems - I. New detections and limits for intervening and associated absorbers
Bouché, Nicolas; York, Donald G.; Kulkarni, Varsha P. +2 more
Detailed studies of damped and sub-damped Lyman α systems (DLAs), the galaxies probed by the absorption they produce in the spectra of background quasars, rely on identifying the galaxy responsible for the absorber with more traditional methods. Integral field spectroscopy provides an efficient way of detecting faint galaxies near bright quasars, …
Does the F10.7 index correctly describe solar EUV flux during the deep solar minimum of 2007-2009?
Liu, Libo; Wan, Weixing; Chen, Yiding
This paper shows that the relationship between solar EUV flux and the F10.7 index during the extended solar minimum (Smin) of 2007-2009 is different from that in the previous Smin. This difference is also seen in the relationship between foF2 and F10.7. We collected SOHO/SEM EUV observations and the F