[ITAL]Hubble Space Telescope[/ITAL] Imaging of [CLC][ITAL]z[/ITAL] ≥ 0.4[/CLC] Quasar Host Galaxies Selected by Quasar Radio and Optical Properties

1997 ◽  
Vol 480 (2) ◽  
pp. L95-L08 ◽  
Author(s):  
Eric J. Hooper ◽  
Chris D. Impey ◽  
Craig B. Foltz

2019 ◽  
Vol 486 (3) ◽  
pp. 3105-3117 ◽  
Author(s):  
A A Chrimes ◽  
A J Levan ◽  
E R Stanway ◽  
J D Lyman ◽  
A S Fruchter ◽  
...  

Abstract We present a study of 21 dark gamma-ray burst (GRB) host galaxies, predominantly using X-ray afterglows obtained with the Chandra X-Ray Observatory (CXO) to precisely locate the burst in deep Hubble Space Telescope (HST) imaging of the burst region. The host galaxies are well-detected in F160W in all but one case and in F606W imaging in 60 per cent of cases. We measure magnitudes and perform a morphological analysis of each galaxy. The asymmetry, concentration, and ellipticity of the dark burst hosts are compared against the host galaxies of optically bright GRBs. In agreement with other studies, we find that dark GRB hosts are redder and more luminous than the bulk of the GRB host population. The distribution of projected spatial offsets for dark GRBs from their host galaxy centroids is comparable to that of optically bright bursts. The dark GRB hosts are physically larger, more massive and redder, but are morphologically similar to the hosts of bright GRBs in terms of concentration and asymmetry. Our analysis constrains the fraction of high redshift (z > 5) GRBs in the sample to 14 per cent, implying an upper limit for the whole long-GRB population of ≤4.4 per cent. If dust is the primary cause of afterglow darkening amongst dark GRBs, the measured extinction may require a clumpy dust component in order to explain the observed offset and ellipticity distributions.



2017 ◽  
Vol 475 (3) ◽  
pp. 3213-3239 ◽  
Author(s):  
D Lawther ◽  
M Vestergaard ◽  
X Fan


2021 ◽  
Vol 922 (2) ◽  
pp. 178
Author(s):  
Jared R. Rice ◽  
Blagoy Rangelov ◽  
Andrea Prestwich ◽  
Rupali Chandar ◽  
Luis Bichon ◽  
...  

Abstract We used archival data from the Chandra X-ray Observatory (Chandra) and the Hubble Space Telescope, to identify 334 candidate X-ray binary systems and their potential optical counterparts in the interacting galaxy pair NGC 5194/5195 (M51). We present the catalog and data analysis of X-ray and optical properties for those sources, from the deep 892 ks Chandra observations, along with the magnitudes of candidate optical sources as measured in the 8.16 ks Hubble Space Telescope observations. The X-ray luminosity function of the X-ray sources above a few times 1036 erg s−1 follows a power law N ( > L X , b ) ∝ L X , b 1 − α with α = 1.65 ± 0.03. Approximately 80% of sources are variable over a 30 day window. Nearly half of the X-ray sources (173/334) have an optical counterpart within 0.″5.



2013 ◽  
Vol 9 (S304) ◽  
pp. 363-370
Author(s):  
Yervant Terzian ◽  
Edward Khachikian

AbstractIt is known that among active galaxies (AG) with strong emission lines (UV-galaxies, Sy1 and Sy2, Markarian and Kazarian galaxies, radio-galaxies, QSOs host galaxies and so on) there is a large percentage of objects with double and multiple (or complex) nuclei. The common sizes of these nuclei are of the order of a few hundred parsecs or kiloparsecs. We shall discuss the results of morphological and spectroscopic observations of a number of “active galaxies” carried out with the 5m Palomar telescope, 2.6m telescope of Ambartsumian Byurakan Astrophysical Observatory, 6m telescope of Special Astrophysical Observatory in Russia, and newer Hubble Space Telescope data.





1999 ◽  
Vol 183 ◽  
pp. 17-30 ◽  
Author(s):  
Wendy L. Freedman ◽  
Jeremy R. Mould ◽  
Robert C. Kennicutt ◽  
Barry F. Madore

A Joint Discussion on the extragalactic distance scale and the Hubble constant took place fifteen years ago, at the 1982 XVIIIth General Assembly of the IAU, held in Patras, Greece. At that time, the newest applications of infrared photometers to Tully-Fisher measurements (Aaronson 1983) and Cepheid distances (Madore 1983) were reported. CCDs were just coming into use and had not yet been applied to extragalactic distance determinations; all of the extragalactic Cepheid distances were based on photographic Argelander (eye-estimated) photometry (Tammann and Sandage 1983 and references therein). No Cepheid distances to type Ia supernova-host galaxies were available.



Author(s):  
Miriam Garcia ◽  
Christopher J. Evans ◽  
Joachim M. Bestenlehner ◽  
Jean Claude Bouret ◽  
Norberto Castro ◽  
...  

AbstractCosmic history has witnessed the lives and deaths of multiple generations of massive stars, all of them invigorating their host galaxies with ionizing photons, kinetic energy, fresh material, and stellar-mass black holes. Ubiquitous engines as they are, astrophysics needs a good understanding of their formation, evolution, properties and yields throughout the history of the Universe, and with decreasing metal content mimicking the environment at the earliest epochs. Ultimately, a physical model that could be extrapolated to zero metallicity would enable tackling long-standing questions such as “What did the first, very massive stars of the Universe look like?” or “What was their role in the re-ionization of the Universe?” Yet, most of our knowledge of metal-poor massive stars is drawn from one single point in metallicity. Massive stars in the Small Magellanic Cloud (SMC, $\sim $ ∼ 1/5Z⊙ ) currently serve as templates for low-metallicity objects in the early Universe, even though significant differences with respect to massive stars with poorer metal content have been reported. This White Paper summarizes the current knowledge on extremely (sub-SMC) metal poor massive stars, highlighting the most outstanding open questions and the need to supersede the SMC as standard. A new paradigm can be built from nearby extremely metal-poor galaxies that make a new metallicity ladder, but massive stars in these galaxies are out of reach to current observational facilities. Such a task would require an L-size mission, consisting of a 10m-class space telescope operating in the optical and the ultraviolet ranges. Alternatively, we propose that ESA unites efforts with NASA to make the LUVOIR mission concept a reality, thus continuing the successful partnership that made the Hubble Space Telescope one of the greatest observatories of all time.



2015 ◽  
Vol 11 (A29B) ◽  
pp. 259-260
Author(s):  
Charlotte R. Angus ◽  
Andrew J. Levan ◽  
Daniel A. Perley

AbstractSuperluminous supernovae (SLSNe) are an emerging class of SNe that exhibit luminosities exceeding those of SN Ia by an order of magnitude and have light curves with characteristic timescales of hundreds of days. Here we present observations of the host galaxies of 21 SLSNe observed with the Hubble Space Telescope, and show that their ultraviolet (UV) and near-infrared (nIR) luminosities and sizes and very different from those of the hosts of other core collapse events, with significant implications for their progenitors.



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