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Related papers: Host galaxies and environment of BL Lac objects

200 papers

We present optical images and spectroscopy for a dozen of BL Lac objects. Most of these objects were not previously studied and we give for the first time the properties of their host galaxies. The properties of the new host galaxies are…

Astrophysics · Physics 2009-09-25 Renato Falomo , Marie-Helene Ulrich

Near-infrared and optical imaging of BL Lac host galaxies is used to investigate their colour properties. We find that the R-H colour and colour gradient distributions of the BL Lac hosts are much wider than those for normal ellipticals,…

Astrophysics · Physics 2009-11-10 J. K. Kotilainen , R. Falomo

(abridged) We present near-infrared Ks-band imaging of 13 high redshift (0.6 < z < 1.3) BL Lac objects. We clearly detect the host in eight objects, and marginally in three others. In all cases, the host galaxy is well represented by an…

Astrophysics · Physics 2009-11-11 J. K. Kotilainen , T. Hyvonen , R. Falomo

Snapshot images of about 100 BL Lac objects were obtained with WFPC2 on HST. Sources from various samples, in the redshift range 0.05 to 1.2, were observed and 61 resolved (51 with known z). The high resolution and homogeneity of the images…

Astrophysics · Physics 2016-08-30 R. Falomo , C. Megan Urry , Riccardo Scarpa , Joseph E. Pesce , Aldo Treves

Host galaxies are an excellent means of probing the natal environments that generate gamma-ray bursts (GRBs). Recent work on the host galaxies of short-duration GRBs has offered new insights into the parent stellar populations and ages of…

High Energy Astrophysical Phenomena · Physics 2015-06-04 Emily M. Levesque

We report on a large HST imaging survey of BL Lac objects, at spatial resolution ~10 times better than previous ground-based surveys. We focus on data reduction and analysis, describing the procedures used to model the host galaxy surface…

Astrophysics · Physics 2009-10-31 Riccardo Scarpa , C. Megan Urry , Renato Falomo , Joseph E. Pesce , Aldo Treves

Host galaxies are an excellent means of probing the natal environments that generate gamma-ray bursts (GRBs). Surveys of long-duration GRB (LGRB) host environments and their ISM properties have produced intriguing new results with important…

High Energy Astrophysical Phenomena · Physics 2012-06-15 Emily M. Levesque

Multiwavelength data on star-forming galaxies provide strong evidence for large-scale galactic winds in both nearby and distant objects. The results from recent ground-based and space-borne programs are reviewed. The impact of these winds…

Astrophysics · Physics 2007-05-23 Sylvain Veilleux

We report on the optical properties of a sample of 30 BL Lac host galaxies in the redshift range $0.03<z<0.2$, as derived from HST observations. All galaxies are fully resolved in the WFPC2 (F702W filter) images, allowing a quantitative…

Astrophysics · Physics 2009-10-31 R. Falomo , R. Scarpa , A. Treves , C. M. Urry

The past 20 years have seen phenomenal progress in our understanding of BL Lac objects. They form part of the blazar class, which are radio-loud AGN whose relativistic jets are aligned along our line of sight. Several critical milestones…

Astrophysics · Physics 2007-05-23 C. Megan Urry

It is now widely established that globular clusters host robust populations of white dwarfs, neutron stars, and black holes throughout their lifetimes. Within clusters, dynamical processes enabled by stellar densities thousands to millions…

High Energy Astrophysical Phenomena · Physics 2025-08-21 Kyle Kremer

We investigate the environments of galaxies around BL Lac objects and FR I radiogalaxies, the alleged parent populations of misaligned sources. We compare the environment of a sample of 50 BL Lac objects at 0.1<z<0.33 with that of a sample…

High Energy Astrophysical Phenomena · Physics 2019-04-10 A. Sandrinelli , R. Falomo , A. Treves

BL Lac objects are active nuclei, hosted in massive elliptical galaxies, the emission of which is dominated by a relativistic jet closely aligned with the line of sight. This implies the existence of a parent population of sources with a…

High Energy Astrophysical Phenomena · Physics 2016-11-26 Renato Falomo , Elena Pian , Aldo Treves

In this book-chapter we first briefly discuss some basic observational issues related to what a GRB host galaxy is (whether they are operationally well defined as a class) and sample completeness. We then describe some of the early studies…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-21 Johan P. U. Fynbo , Daniele Malesani , Páll Jakobsson

This Meeting featured the recent advancements in our understanding of galaxy clusters and the distant Universe, achieved by the past and new generation of X-ray satellites. I summarize here the main themes that have been discussed: (a)…

Astrophysics · Physics 2007-05-23 Stefano Borgani

A clear insight of the galaxies hosting active galactic nuclei is of fundamental importance for understanding the processes of galaxies and nuclei formation and their cosmic evolution. A good characterization of the host galaxies properties…

Astrophysics · Physics 2009-11-07 N. Carangelo , R. Falomo , A. Treves

The BL Lac object RGB 1745+398 lies in an environment that makes it possible to study the cluster around it more deeply than the environments of other BL Lac objects. The cluster centered on the BL Lac works as a strong gravitational lens,…

Astrophysics · Physics 2009-11-13 H. Lietzen , K. Nilsson , L. O. Takalo , P. Heinamaki , P. Nurmi , P. Keinanen , S. Wagner

The HST snapshot imaging survey of 110 BL Lac objects (Urry et al. 2000) has clearly shown that the host galaxies are massive and luminous ellipticals. The dispersion of the absolute magnitudes is sufficiently small, so that the measurement…

Astrophysics · Physics 2009-11-13 B. Sbarufatti , A. Treves , R. Falomo

This paper reviews some recent work on the properties of the outer halos of galaxies. I particularly focus on recent and upcoming advances made with the study of globular clusters. Globular clusters can be observed out to ~100 kpc from the…

Astrophysics · Physics 2017-08-23 Stephen E. Zepf

Star clusters are fundamental units of stellar feedback and unique tracers of their host galactic properties. In this review, we will first focus on their constituents, i.e.\ detailed insight into their stellar populations and their…

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