Search Publications
Charged particle signatures of the diamagnetic cavity of comet 67P/Churyumov-Gerasimenko
Szego, K.; Goetz, C.; Henri, P. +9 more
One of the scientific objectives of the Rosetta mission is to investigate the diamagnetic cavity of comet 67P/Churyumov-Gerasimenko. We employed combined data of several instruments of the Rosetta Plasma Consortium to identify and study diamagnetic cavity crossing events. Using electron data from the Ion Electron Sensor to complement the Magnetome…
Wolf-Rayet stars in M81: detection and characterization using GTC/OSIRIS spectra and HST/ACS images
Gómez-González, V. M. A.; Mayya, Y. D.; Rosa-González, D.
We here report the properties of Wolf-Rayet (W-R) stars in 14 locations in the nearby spiral galaxy M81. These locations were found serendipitously while analysing the slit spectra of a sample of ∼150 star-forming complexes, taken using the long-slit and multiobject spectroscopic modes of the OSIRIS instrument at the 10.4-m Gran Telescopio Canaria…
Mt. Wendelstein imaging of the post-perihelion dust coma of 67P/Churyumov-Gerasimenko in 2015/2016
Hopp, Ulrich; Riffeser, Arno; Kluge, Matthias +3 more
Comet 67P/Churyumov-Gerasimenko (67P) was imaged with the 2 m telescope at Mt. Wendelstein Observatory in the Alps. Coma and tail monitoring was performed during 51 nights between 2015 August 22 and 2016 May 9. The images through r and I Sloan Digital Sky Survey (SDSS) filters show the dust distribution around the comet, while images in the SDSS g…
Optical and near-infrared observations of SN 2014ck: an outlier among the Type Iax supernovae
Howell, D. A.; Kankare, E.; Turatto, M. +18 more
We present a comprehensive set of optical and near-infrared (NIR) photometric and spectroscopic observations for SN 2014ck, extending from pre-maximum to six months later. These data indicate that SN 2014ck is photometrically nearly identical to SN 2002cx, which is the prototype of the class of peculiar transients named SNe Iax. Similar to SN 2002…
Recurring X-ray outbursts in the supernova impostor SN 2010da in NGC 300
Skillman, E. D.; Kong, A. K. H.; Williams, B. F. +4 more
We present new observations of the `supernova impostor' SN 2010da using the Chandra X-ray Observatory and the Hubble Space Telescope. During the initial 2010 outburst, the 0.3-10 keV luminosity was observed by Swift to be ∼5 × 1038 erg s-1 and faded by a factor of ∼25 in a four month period. Our two new Chandra observations s…
Optical and NIR observations of the nearby type Ia supernova SN 2014J
Ojha, D. K.; Anupama, G. C.; Prabhu, T. P. +4 more
Optical and NIR observations of the Type Ia supernova SN 2014J in M82 are presented. The observed light curves are found to be similar to normal Type Ia supernovae (SNe Ia), with a decline rate parameter Δm15(B) = 1.08 ± 0.03. The supernova reached B-band maximum on JD 2456690.14, at an apparent magnitude mB(max) = 11.94. The…
Cosmic microwave background acoustic peak locations
Knox, L.; Narimani, A.; Pan, Z. +1 more
The Planck collaboration has measured the temperature and polarization of the cosmic microwave background well enough to determine the locations of eight peaks in the temperature (TT) power spectrum, five peaks in the polarization (EE) power spectrum and 12 extrema in the cross (TE) power spectrum. The relative locations of these extrema give a st…
The awakening of the γ-ray narrow-line Seyfert 1 galaxy PKS 1502+036
Pearson, T. J.; Giroletti, M.; Readhead, A. C. S. +7 more
After a long low-activity period, a γ-ray flare from the narrow-line Seyfert 1 PKS 1502+036 (z = 0.4089) was detected by the Large Area Telescope (LAT) on board Fermi in 2015. On 2015 December 20, the source reached a daily peak flux, in the 0.1-300 GeV band, of (93 ± 19) × 10-8 ph cm-2 s-1, attaining a flux of (23…
A comparative analysis of the observed white dwarf cooling sequence from globular clusters
Kepler, S. O.; Costa, J. E. S.; Montgomery, M. H. +8 more
We report our study of features at the observed red end of the white dwarf cooling sequences for three Galactic globular clusters: NGC 6397, 47 Tucanae and M 4. We use deep colour-magnitude diagrams constructed from archival Hubble Space Telescope (Advanced Camera for Surveys) to systematically investigate the blue turn at faint magnitudes and the…
KAT-7 observations of an unbiased sample of mass-selected galaxy clusters
Brunetti, G.; Venturi, T.; Dallacasa, D. +7 more
The presence of megaparsec-scale radio haloes in galaxy clusters has already been established by many observations over the last two decades. The emerging explanation for the formation of these giant sources of diffuse synchrotron radio emission is that they trace turbulent regions in the intracluster medium, where particles are trapped and accele…