Search Publications
Further deep imaging of HR 7329 A (η Tel A) and its brown dwarf companion B
Neuhäuser, R.; Schmidt, T. O. B.; Ginski, C. +1 more
About 4 arcsec south of the young A0-type star HR 7329, a faint companion candidate was found by Lowrance et al. Its spectral type of M7-8 is consistent with a young brown dwarf companion. Here we report 10 new astrometric imaging observations of the pair HR 7329 A and B, obtained with the Hubble Space Telescope and the Very Large Telescope, aimed…
Star cluster formation and evolution in Mrk 930: properties of a metal-poor starburst
Östlin, G.; Adamo, A.; Zackrisson, E. +4 more
We present the analysis of the large population of star clusters in the blue compact galaxy (BCG) Mrk 930. The study has been conducted by means of a photometric analysis of multiband data obtained with the Hubble Space Telescope (HST). We have reconstructed the spectral energy distributions of the star clusters and estimated the age, mass and ext…
The core-collapse supernova rate in Arp 299 revisited
Kankare, E.; Alberdi, A.; Ryder, S. D. +3 more
We present a study of the core-collapse supernova (CCSN) rate in nuclei A and B1, of the luminous infrared galaxy (LIRG) Arp 299, based on ∼11 yr of Very Large Array (VLA) monitoring of their radio emission at 8.4 GHz. Significant variations in the nuclear radio flux density can be used to identify the CCSN activity in the absence of high-resoluti…
A cold component and the complex velocity structure of DLA1331 + 170
Carswell, R. F.; Murphy, M. T.; Wolfe, A. M. +1 more
We examine the velocity structure in the gas associated with H I in the damped Lyα absorption system at redshift z= 1.7764 towards the QSO 1331 + 170 using Arecibo H I 21-cm data, optical spectra from the Keck High Resolution Echelle Spectrograph (HIRES) and European Southern Observatory (ESO) Very Large Telescope (VLT) Ultraviolet and Visual Eche…
Accretion states of the Galactic microquasar GRS 1758-258
Soria, Roberto; Pottschmidt, Katja; Mehdipour, Missagh +4 more
We present the results of a radio and X-ray study of the Galactic microquasar GRS 1758-258, using unpublished archival data and new observations. We focus in particular on the 2000-2002 state transitions, and on its more quiet behaviour in 2008-2009. Our spectral and timing analysis of the XMM-Newton data shows that the source was in the canonical…
The AKARI Deep Field-South: Spitzer 24- and 70-µm observations, catalogues and counts
Clements, D. L.; Pearson, C.; Shirahata, M. +3 more
The AKARI Deep Field-South (ADF-S) is a ∼12 deg2 region near the South Ecliptic Pole that has been observed with deep scans in the far-infrared by the AKARI satellite. As such it is becoming one of the key extragalactic survey fields. We here present complementary observations of the ADF-S conducted by the Spitzer Space Telescope at wav…
X-ray calibration of Sunyaev-Zel'dovich scaling relations with the ACCEPT catalogue of galaxy clusters observed by Chandra
Comis, B.; de Petris, M.; Lamagna, L. +2 more
We explore the scaling relation between the flux of the Sunyaev-Zel'dovich (SZ) effect and the total mass of galaxy clusters using already reduced Chandra X-ray data present in the ACCEPT (Archive of Chandra Cluster Entropy Profile Tables) catalogue. The analysis is conducted over a sample of 226 objects, examining the relatively small scale corre…
Swift monitoring of the central X-ray source in RCW 103
de Luca, A.; Esposito, P.; Possenti, A. +3 more
The X-ray source 1E 161348-5055 lies at the centre of the 2-kyr-old supernova remnant RCW 103. Owing to its 24-ks modulation, orders-of-magnitude flux variability over a few months/years and lack of an obvious optical counterpart, 1E 161348-5055 defies assignment to any known class of X-ray sources. Starting from 2006 April, Swift observed 1E 1613…
Resolving the nuclear dust distribution of the Seyfert 2 galaxy NGC 3081
Altieri, B.; Valtchanov, I.; Esquej, P. +13 more
We report far-infrared (FIR) imaging of the Seyfert 2 galaxy NGC 3081 in the range 70-500 µm, obtained with an unprecedented angular resolution, using the Herschel Space Observatory instruments PACS and SPIRE. The 11 kpc (∼70 arcsec) diameter star-forming ring of the galaxy appears resolved up to 250 µm. We extracted IR (1.6-500 µ…
X-ray study of HLX1: intermediate-mass black hole or foreground neutron star?
Soria, Roberto; Wu, Kinwah; Zampieri, Luca +1 more
We re-assess the XMM-Newton and Swift observations of HLX1 to examine the evidence for its identification as an intermediate-mass black hole. We show that the X-ray spectral and timing properties are equally consistent with an intermediate-mass black hole in a high state or with a foreground neutron star with a luminosity ∼ a few ×1032 …