Search Publications
Updated theoretical period-age and period-age-colour relations for Galactic Classical Cepheids: an application to the Gaia DR2 sample
Marconi, Marcella; Molinaro, Roberto; Ripepi, Vincenzo +4 more
Updated evolutionary and pulsational model predictions are combined in order to interpret the properties of Galactic Classical Cepheids in the Gaia Data Release 2. In particular, the location of the instability strip boundaries and the analytical relations connecting pulsation periods to the intrinsic stellar parameters are combined with evolution…
The X-ray view of merger-induced active galactic nuclei activity at low redshift
Ellison, Sara L.; Blecha, Laura; Satyapal, Shobita +1 more
Galaxy mergers are predicted to trigger accretion on to the central supermassive black holes, with the highest rates occurring during final coalescence. Previously, we have shown elevated rates of both optical and mid-IR selected active galactic nuclei (AGNs) in post-mergers, but to date the prevalence of X-ray AGNs has not been examined in the sa…
X-ray spectroscopy of the γ-ray brightest nova V906 Car (ASASSN-18fv)
Strader, Jay; Chomiuk, Laura; Ness, Jan-Uwe +15 more
Shocks in γ-ray emitting classical novae are expected to produce bright thermal and non-thermal X-rays. We test this prediction with simultaneous NuSTAR and Fermi/LAT observations of nova V906 Car, which exhibited the brightest GeV γ-ray emission to date. The nova is detected in hard X-rays while it is still γ-ray bright, but contrary to simple th…
The slow demise of the long-lived SN 2005ip
Van Dyk, Schuyler D.; Filippenko, Alexei V.; Kilpatrick, Charles D. +16 more
The Type IIn supernova (SN IIn) 2005ip is one of the most well-studied and long-lasting examples of an SN interacting with its circumstellar environment. The optical light curve plateaued at a nearly constant level for more than five years, suggesting ongoing shock interaction with an extended and clumpy circumstellar medium (CSM). Here, we presen…
Exploring the differences of integrated and spatially resolved analysis using integral field unit data: the case of Abell 14
Akras, Stavros; Monteiro, Hektor; Aleman, Isabel +3 more
We present a new approach to study planetary nebulae using integral field spectroscopy. VLT@VIMOS datacube of the planetary nebula Abell 14 is analysed in three different ways by extracting: (I) the integrated spectrum, (II) one-dimensional simulated long-slit spectra for different position angles, and (III) spaxel-by-spaxel spectra. These data ar…
A complete catalogue of dusty supernova remnants in the Galactic plane
De Looze, I.; Rho, J.; Dunne, L. +9 more
We search for far-infrared (FIR) counterparts of known supernova remnants (SNRs) in the Galactic plane (360° in longitude and $b = \pm \, 1^{\circ }$ ) at 70-500 µm with Herschel. We detect dust signatures in 39 SNRs out of 190, made up of 13 core-collapse supernovae (CCSNe), including 4 Pulsar Wind Nebulae (PWNe), and 2 Type Ia SNe. A furth…
A radio polarimetric study to disentangle AGN activity and star formation in Seyfert galaxies
O'Dea, C. P.; Baum, S. A.; Kharb, P. +2 more
To understand the origin of radio emission in radio-quiet active galactic nucleus (AGN) and differentiate between the contributions from star formation, AGN accretion, and jets, we have observed a nearby sample of Seyfert galaxies along with a comparison sample of starburst galaxies using the Expanded Very Large Array (EVLA) in full-polarization m…
Molecule-dependent oxygen isotopic ratios in the coma of comet 67P/Churyumov-Gerasimenko
Altwegg, K.; Balsiger, H.; Fuselier, S. A. +9 more
The ratios of the three stable oxygen isotopes 16O, 17O, and 18O on the Earth and, as far as we know in the Solar system, show variations on the order of a few per cent at most, with a few outliers in meteorites. However, in the interstellar medium there are some highly fractionated oxygen isotopic ratios in some s…
A search for variable subdwarf B stars in TESS full frame images - I. Variable objects in the southern ecliptic hemisphere
Sahoo, S. K.; Baran, A. S.; Ostrowski, J. +1 more
We report the results of our search for pulsating subdwarf B stars in full frame images, sampled at 30 min cadence and collected during Year 1 of the TESS mission. Year 1 covers most of the southern ecliptic hemisphere. The sample of objects we checked for pulsations was selected from a subdwarf B stars data base available to public. Only two posi…
Cool white dwarfs as standards for infrared observations
Bohlin, Ralph C.; Gentile Fusillo, Nicola Pietro; Kalirai, Jason S. +2 more
In the era of modern digital sky surveys, uncertainties in the flux of stellar standards are commonly the dominant systematic error in photometric calibration and can often affect the results of higher level experiments. The Hubble Space Telescope (HST) spectrophotometry, which is based on computed model atmospheres for three hot (Teff …