Search Publications
Large-scale outflow in quasar LBQS J1206+1052: HST/COS observations
Arav, Nahum; Chamberlain, Carter
Using two orbits of HST/COS archival observations, we measure the location and energetics of a quasar outflow from LBQS J1206+1052. From separate collisional excitation models of observed N III/N III* and S III/S III* troughs, we measure the electron number density n_e of the outflow. Both independent determinations are in full agreement and yield…
The nuclear and extended infrared emission of the Seyfert galaxy NGC 2992 and the interacting system Arp 245
Valtchanov, I.; Esquej, P.; Pérez García, A. M. +14 more
We present subarcsecond resolution infrared (IR) imaging and mid-IR (MIR) spectroscopic observations of the Seyfert 1.9 galaxy NGC 2992, obtained with the Gemini North Telescope and the Gran Telescopio CANARIAS (GTC). The N-band image reveals faint extended emission out to ∼3 kpc, and the polycyclic aromatic hydrocarbon features detected in the GT…
Periodic signals from the Circinus region: two new cataclysmic variables and the ultraluminous X-ray source candidate GC X-1
Sidoli, L.; Esposito, P.; Israel, G. L. +5 more
The examination of two 2010 Chandra ACIS (Advanced CCD Imaging Spectrometer) exposures of the Circinus galaxy resulted in the discovery of two pulsators: CXO J141430.1-651621 and CXOU J141332.9-651756. We also detected 26 ks pulsations in CG X-1, consistently with previous measures. For ∼40 other sources, we obtained limits on periodic modulations…
Galaxy sizes as a function of environment at intermediate redshift from the ESO Distant Cluster Survey
Aragón-Salamanca, Alfonso; Vulcani, Benedetta; Zaritsky, Dennis +5 more
In order to assess whether the environment has a significant effect on galaxy sizes, we compare the mass-size relations of cluster and field galaxies in the 0.4 < z < 0.8 redshift range from the ESO Distant Cluster Survey (EDisCS) using Hubble Space Telescope images. We analyse two mass-selected samples, one defined using photometric redshif…
Supernova-driven outflows in NGC 7552: a comparison of H α and UV tracers
Chisholm, John; Calzetti, Daniela; Leitherer, Claus +3 more
We investigate the supernova-driven galactic wind of the barred spiral galaxy NGC 7552, using both ground-based optical nebular emission lines and far-ultraviolet (UV) absorption lines measured with the Hubble Space Telescope Cosmic Origins Spectrograph. We detect broad (∼300 km s-1) blueshifted (-40 km s-1) optical emission …
The impact of strong gravitational lensing on observed Lyman-break galaxy numbers at 4 ≤ z ≤ 8 in the GOODS and the XDF blank fields
Treu, T.; Trenti, M.; Illingworth, G. D. +5 more
Detections of Lyman-break galaxies (LBGs) at high-redshift are affected by gravitational lensing induced by foreground deflectors not only in galaxy clusters, but also in blank fields. We quantify the impact of strong magnification in the samples of B435, V606, i775 and z850 & Y105 dropout…
The NuSTAR X-ray spectrum of the low-luminosity active galactic nucleus in NGC 7213
Harrison, F. A.; Stern, D.; Bauer, F. E. +11 more
We present an analysis of the 3-79 keV NuSTAR spectrum of the low-luminosity active galactic nucleus NGC 7213. In agreement with past observations, we find a lower limit to the high-energy cut-off of Ec > 140 keV, no evidence for a Compton-reflected continuum and the presence of an iron K α complex, possibly produced in the broad-lin…
J021659-044920: a relic giant radio galaxy at z ∼ 1.3
Beelen, A.; Singh, V.; Ishwara-Chandra, C. H. +4 more
We report the discovery of a relic Giant Radio Galaxy (GRG) J021659-044920 at redshift z ∼ 1.3 that exhibits large-scale extended, nearly co-spatial, radio and X-ray emission from radio lobes, but no detection of Active Galactic Nuclei core, jets and hotspots. The total angular extent of the GRG at the observed frame 0.325 GHz, using Giant Metrewa…
Constraining star formation rates in cool-core brightest cluster galaxies
Combes, Françoise; Mittal, Rupal; Whelan, John T.
We used broad-band imaging data for 10 cool-core brightest cluster galaxies (BCGs) and conducted a Bayesian analysis using stellar population synthesis to determine the likely properties of the constituent stellar populations. Determination of ongoing star formation rates (SFRs), in particular, has a direct impact on our understanding of the cooli…
X-ray spectral and variability properties of low-mass active galactic nuclei
Fabian, A. C.; Miniutti, G.; Cackett, E. M. +3 more
We study the X-ray properties of a sample of 14 optically selected low-mass active galactic nuclei (AGN) whose masses lie within the range 105-2 × 106 M⊙ with XMM-Newton. Only six of these low-mass AGN have previously been studied with sufficient quality X-ray data, thus, we have more than double the number of low-…