Zobrazeno 1 - 10
of 91
pro vyhledávání: '"Biretta, J"'
Autor:
Meyer, Eileen T., Sparks, W. B., Biretta, J. A., Anderson, Jay, Sohn, Sangmo Tony, van der Marel, Roeland P., Norman, Colin, Nakamura, Masanori
We report new results from an HST archival program to study proper motions in the optical jet of the nearby radio galaxy M87. Using over 13 years of archival imaging, we reach accuracies below 0.1c in measuring the apparent velocities of individual k
Externí odkaz:
http://arxiv.org/abs/1308.4633
Publikováno v:
Astrophysical Journal 699 (2009) 305-314; http://stacks.iop.org/0004-637X/699/305
We investigate the variability timescales in the jet of M87 with two goals. The first is to use the rise times and decay times in the radio, ultraviolet and X-ray lightcurves of HST-1 to constrain the source size and the energy loss mechanisms affect
Externí odkaz:
http://arxiv.org/abs/0904.3925
Autor:
Harris, D. E., Cheung, C. C., Stawarz, L., Biretta, J. A., Sparks, W., Perlman, E. S., Wilson, A. S.
We review the recent data on the knot HST-1 in the M87 jet in the context of typical blazar behavior. In particular we discuss the wide-band flare of 2005 which peaked at a factor of 50 to 80 times the intensity observed in 2000; the superluminal rad
Externí odkaz:
http://arxiv.org/abs/0707.3124
Autor:
Harris, D. E., Cheung, C. C., Biretta, J. A., Sparks, W., Junor, W., Perlman, E. S., Wilson, A. S.
Publikováno v:
Astrophys.J.640:211-218,2006
The X-ray intensity of knot HST-1, 0.85" from the nucleus of the radio galaxy M87, has increased by more than a factor of 50 during the last 5 years. The optical increase is similar and our more limited radio data indicate a commensurate activity. We
Externí odkaz:
http://arxiv.org/abs/astro-ph/0511755
Publikováno v:
Astron.J.130:1171-1176,2005
The Trifid nebula (M20) is a well-known prominent optical HII region trisected by bands of obscuring dust lanes and excited by an O7.5 star HD 164492A. Previous near-IR, mid-IR and radio continuum observations of the cluster of stars at the center of
Externí odkaz:
http://arxiv.org/abs/astro-ph/0505155
Publikováno v:
Astrophys.J. 624 (2005) 246-253
HH 399 is one of the first Herbig Haro flows recognized to be irradiated by the UV radiation of the massive O7.5 star in the Trifid nebula. We present the proper motion of the first irradiated jet based on two epochs of HST observations of HH 399 sep
Externí odkaz:
http://arxiv.org/abs/astro-ph/0501172
Publikováno v:
Astrophys.J. 586 (2003) L41-L44
We present Chandra X-ray monitoring of the M87 jet in 2002, which shows that the intensity of HST-1, an optical knot 0.8" from the core, increased by a factor of two in 116 days and a factor of four in 2 yrs. There was also a significant flux decreas
Externí odkaz:
http://arxiv.org/abs/astro-ph/0302270
Publikováno v:
MPE Report 271, October 1999, page 111
ROSAT High Resolution Imager (HRI) data from eight observations have been co-added to obtain an effective exposure of 230 ksec. We have identified a number of features and regions with excess X-ray brightness over that from a circularly symmetric mod
Externí odkaz:
http://arxiv.org/abs/astro-ph/0002464
Beginning in 1995 June, we have obtained an observation of M87 with the ROSAT High Resolution Imager (HRI) every 6 months. We present the measurements of X-ray intensity for the core and knot A through 1998 January. We find significant changes in bot
Externí odkaz:
http://arxiv.org/abs/astro-ph/9804201
We describe asymmetrical features in a long exposure X-ray map of M87 made with the ROSAT High Resolution Imager (HRI). A bright triangular region is marked by a linear `spur' along one edge. The structure of this spur suggests an interpretation of a
Externí odkaz:
http://arxiv.org/abs/astro-ph/9804200