Search Publications
A far-ultraviolet variable with an 18-minute period in the globular cluster NGC 1851
Maccarone, T. J.; Knigge, C.; Sarajedini, A. +5 more
We present the detection of a variable star with an 18.05 min period in far-ultraviolet (FUV) images of the globular cluster NGC 1851 taken with the Hubble Space Telescope (HST). A candidate optical counterpart lies on the red horizontal branch or the asymptotic giant branch star of the cluster, but it is statistically possible that this is a chan…
Dependence of the broad Fe Kα line on the physical parameters of AGN
Lu, Youjun; Liu, Zhu; Yuan, Weimin +3 more
In this paper, the dependence of the broad Fe Kα line on the physical parameters of AGN, such as the black hole mass MBH, accretion rate (equivalently represented by Eddington ratio λEdd) and optical classification is investigated by applying the X-ray spectra stacking method to a large sample of AGN which have well measured …
Tidal bridge and tidal dwarf candidates in the interacting system Arp194
Egorov, Oleg V.; Zasov, Anatoly V.; Saburova, Anna S. +1 more
Arp194 is a system of recently collided galaxies, where the southern galaxy (S) passed through the gaseous disc of the northern galaxy (N) which in turn consists of two close components. This system is of special interest due to the presence of regions of active star formation in the bridge between galaxies, the brightest of which (the region A) h…
The young nuclear stellar disc in the SB0 galaxy NGC 1023
Morelli, L.; Dalla Bontà, E.; Corsini, E. M. +3 more
Small kinematically decoupled stellar discs with scalelengths of a few tens of parsec are known to reside in the centre of galaxies. Different mechanisms have been proposed to explain how they form, including gas dissipation and merging of globular clusters. Using archival Hubble Space Telescope imaging and ground-based integral-field spectroscopy…
Linking the structural properties of galaxies and their star formation histories with STAGES
Bell, Eric F.; Wolf, Christian; Aragón-Salamanca, Alfonso +5 more
We study the links between star formation history and structure for a large mass-selected galaxy sample at 0.05 ≤ zphot ≤ 0.30. The galaxies inhabit a very broad range of environments, from cluster cores to the field. Using Hubble Space Telescope (HST) images, we quantify their structure following Hoyos et al., and divide them into dist…
Starbursting brightest cluster galaxy: a Herschel view of the massive cluster MACS J1931.8-2634
Altieri, B.; Valtchanov, I.; Grillo, C. +9 more
We investigate the dust-obscured star formation (SF) properties of the massive, X-ray-selected galaxy cluster MACS J1931.8-2634 at z = 0.352. Using far-infrared (FIR) imaging in the range 100-500 µm obtained with the Herschel telescope, we extract 31 sources (2σ) within r ∼ 1 Mpc from the brightest cluster galaxy (BCG). Among these sources, …
XMM-Newton large programme on SN1006 - II. Thermal emission
Vink, Jacco; Miceli, Marco; Bocchino, Fabrizio +2 more
Based on the XMM-Newton large programme on SN1006 and our newly developed tools for spatially resolved spectroscopy analysis as described in Li et al. (Paper I), we study the thermal emission from interstellar medium (ISM) and ejecta of SN1006 by analysing the spectra extracted from 583 tessellated regions dominated by thermal emission. With some …
Triple-ionized carbon associated with the low-density neutral hydrogen gas at 1.7 < z < 3.3: the integrated N H I-N C IV relation
Cristiani, S.; Carswell, R. F.; Kim, T. -S. +4 more
From the Voigt profile fitting analysis of 183 intervening {C IV} systems at 1.7 < z < 3.3 in 23 high-quality UVES/VLT and HIRES/Keck QSO spectra, we find that a majority of {C IV} systems (∼75 per cent) display a well-characterized scaling relation between integrated column densities of {H I} and {C IV} with a negligible redshift evolution,…
Near-infrared observations of PSR J1357-6429
Mennickent, R. E.; Zharikov, S.; Kirichenko, A. +3 more
PSR J1357-6429 is a young radio pulsar that has been detected in the X-ray and γ-ray bands. We present high spatial resolution near-infrared imaging of the pulsar field in the J, H and Ks bands obtained using the VLT/NaCo with the Adaptive Optic system. We found a faint source at the most precise pulsar radio position, which we propose …
Multiwavelength study of RX J2015.6+3711: a magnetic cataclysmic variable with a 2-h spin period
Campana, S.; de Martino, D.; Rea, N. +4 more
The X-ray source RX J2015.6+3711 was discovered by ROSAT in 1996 and recently proposed to be a cataclysmic variable (CV). Here, we report on an XMM-Newton observation of RX J2015.6+3711 performed in 2014, where we detected a coherent X-ray modulation at a period of 7196 ± 11 s and discovered other significant (>6σ) small-amplitude periodicities…