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Related papers: The Radio Corona of AR Lacertae

200 papers

We observed the coronally active eclipsing binary, AR Lac, with the High Energy Transmission Grating on Chandra for a total of 97 ks, spaced over five orbits, at quadratures and conjunctions. Contemporaneous and simultaneous EUV spectra and…

This paper reports on the X-ray emission from BL Lacertae during its July 1997 outburst as observed with the Rossi X-ray Timing Explorer (RXTE), compares the RXTE data to previous measurements, and interprets the overall electromagnetic…

Astrophysics · Physics 2022-01-26 G. Madejski , M. Sikora , T. Jaffe , M. Blazejowski , K. Jahoda , R. Moderski

(Abridged) We present the results from new 15 ks Chandra-ACIS and 4.9 GHz Very Large Array observations of 13 galaxies hosting low luminosity AGN. This completes the multiwavelength study of a sample of 51 nearby early-type galaxies…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Preeti Kharb , A. Capetti , D. J. Axon , M. Chiaberge , P. Grandi , A. Robinson , G. Giovannini , B. Balmaverde , D. Macchetto , R. Montez

We present high angular resolution Very Large Array multi-epoch continuum observations at 3.6 cm and 7 mm towards the core of the L723 multipolar outflow revealing a multiple system of four radio sources suspected to be YSOs in a region of…

We report here on multi-frequency VLBA observations of three extragalactic sources within 1 degree of the Galactic Center. These sources have been used as astrometric reference sources for VLA and VLBA determinations of the proper motion of…

Astrophysics · Physics 2016-08-30 Geoffrey C. Bower , Donald C. Backer , Richard A. Sramek

We present lightcurves obtained in X-ray by the XMM-Newton EPIC cameras and simultaneous radio lightcurves obtained with the VLA for five active M-type flare stars. A number of flare events were observed, and by comparing radio with X-ray…

Astrophysics · Physics 2009-11-10 K. W. Smith , M. Guedel , M. Audard

We present the observational results from the 43-GHz Very Long Baseline Array (VLBA) observations of 124 compact radio-loud active galactic nuclei (AGNs) that were conducted between 2014 November and 2016 May. The typical dimensions of the…

High Energy Astrophysical Phenomena · Physics 2020-07-07 X. -P. Cheng , T. An , S. Frey , X. -Y. Hong , X. He , K. I. Kellermann , M. L. Lister , B. -Q. Lao , X. -F. Li , P. Mohan , J. Yang , X. -C. Wu , Z. -L. Zhang , Y. -K. Zhang , W. Zhao

We present initial results from the 4.8 GHz Very Long Baseline Array (VLBA) survey of the JWST North Ecliptic Pole Time-Domain Field (TDF). From 106 radio sources found in the Karl G. Jansky Very Large Array observations in the TDF, we…

We report the variable X-ray emission from BL Lacertae detected in the ASCA ToO observation conducted during the EGRET and RXTE pointings, coincident with the 1997 July outburst. The source showed a historically high state of X-ray,…

Astrophysics · Physics 2009-10-31 C. Tanihata , T. Takahashi , J. Kataoka , G. M. Madejski , S. Inoue , H. Kubo , F. Makino , J. R. Mattox , N. Kawai

We observed 20 Palomar-Green (PG) quasars at low redshift ($z<0.5$) with total flux density > 1 mJy, including 4 radio-loud quasars (RLQs) and 16 radio-quiet quasars (RQQs), using the Very Long Baseline Array (VLBA) at 5 GHz. Ten RQQs are…

Astrophysics of Galaxies · Physics 2022-11-01 Ailing Wang , Tao An , Xiaopeng Cheng , Luis C. Ho , Kenneth I. Kellermann , Willem A. Baan , Jun Yang , Yingkang Zhang

We present Very Large Array (VLA) observations at 1.4 GHz and 5 GHz of a sample of 12 Quasi-stellar Objects (QSOs) at z = 3.99 to 4.46. The sources were selected as the brightest sources at 250 GHz from the recent survey of Omont et al.…

Astrophysics · Physics 2009-11-06 C. L. Carilli , F. Bertoldi , A. Omont , P. Cox , R. G. McMahon , K. G. Isaak

We employed the Very Large Array (VLA) of the National Radio Astronomy Observatory in C configuration to map 39 ultraluminous IRAS galaxies at 6~cm and 20~cm, at resolutions of ~ 4" and 15", respectively, and 24 sources at 6~cm with in the…

Astrophysics · Physics 2008-11-26 Thomas Crawford , Jon Marr , Bruce Partridge , Michael Strauss

We present and discuss the results of VLBI (EVN) observations of three low-luminosity (P(5 GHz)<10^25 W/Hz) Broad Emission Line AGNs carefully selected from a sample of flat spectrum radio sources (CLASS). Based on the total and the…

Astrophysics · Physics 2009-11-07 A. Caccianiga , M. J. M. Marcha , A. Thean , J. Dennett-Thorpe

Deep radio surveys of extragalactic legacy fields trace a large range of spatial and brightness temperature sensitivity scales, and therefore have differing biases to radio-emitting physical components within galaxies. This is particularly…

We present new radio observations of 9 members of a sample of 29 nearby (z < 0.2) BL Lac objects. The new data have been obtained with the European VLBI Network and/or the MERLIN at 1.6 and 5 GHz and complement previous observations. For…

Astrophysics · Physics 2008-11-26 M. Giroletti , G. Giovannini , G. B. Taylor , R. Falomo

We present sub-arcsecond resolution multi-frequency (8 and 22 GHz) VLA images of five low power compact (LPC) radio sources, and phase referenced VLBA images at 1.6 GHz of their nuclear regions. At the VLA resolution we resolve the…

Astrophysics · Physics 2009-11-11 M. Giroletti , G. Giovannini , G. B. Taylor

Deep radio observations at 1.4GHz for the Extended Chandra Deep Field South were performed in June through September of 2007 and presented in a first data release (Miller et al. 2008). The survey was made using six separate pointings of the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 N. A. Miller , M. Bonzini , E. B. Fomalont , K. I. Kellermann , V. Mainieri , P. Padovani , P. Rosati , P. Tozzi , S. Vattakunnel

VLA imaging at kiloparsec-scale resolution of sixteen core-dominated radio-loud QSOs is presented. Many objects appear to display variable radio emission and their radio morphologies are significantly smaller than those of steep-spectrum…

Astrophysics · Physics 2007-05-23 Peter D. Barthel , Marianne Vestergaard , Colin J. Lonsdale

We present a new sample of 30 nearby (z<0.2) BL Lacs, selected to study the nuclear as well as the large scale properties of low power radio sources. In this first paper, we show and discuss new radio data taken with the VLA (19 objects at…

Astrophysics · Physics 2009-11-10 M. Giroletti , G. Giovannini , G. B. Taylor , R. Falomo

Many massive early-type galaxies host central radio sources and hot X-ray atmospheres indicating the presence of radio-mechanical active galactic nucleus (AGN) feedback. The duty cycle and detailed physics of the radio-mode AGN feedback is…