1996/09/26 by S. S. Eikenberry, Stephen S. Eikenberry, Giovanni G. Fazio +1 · 2 citations
Physics and Astronomy · #Active galactic nucleus #Astronomy and Astrophysical Research #Astrophysical Phenomena and Observations #Flux (metallurgy) #Gamma-ray bursts and supernovae #Infrared #Jet (fluid) #Observatory #Radiative transfer #Synchrotron #Telescope #astro-ph
paper · pdf · doi:10.1086/310450
10 pages, 3 figures; submitted to ApJ Letters
arxiv created 1996/09/26 · openalex publication_date 1997/01/20 · openalex created_date 2016/06/24 · arxiv updated 2016/08/30 · openalex updated_date 2026/08/05
We observed the Galactic microquasar GRS 1915+105 in the K (2.2 μ m) band on 1995 October 16 and 17 UTC using the cryogenic optical bench (COB) infrared imager on the Kitt Peak National Observatory 2.1 m telescope with a 0 2 pixel -1 plate scale and under good (~0 7) seeing conditions. Using a neighboring star in the image frames to determine the point-spread function (PSF), we PSF-subtract the images of GRS 1915+105. We find no evidence of extended emission such as the apparent near-IR jets seen by Sams, Eckart, & Sunyaev in 1995 July. Simple modeling of the star plus jet structure allows us to place an upper limit on any similar emission at that position of K > 16.4 at the 95% confidence level, as compared to K = 13.9 as seen by Sams et al. This lack of extended IR flux during continued hard X-ray flaring activity confirms the hypothesis that the extended IR emission arises from the superluminal radio-emitting jets rather than reprocessing of the X-ray emission on other structures around the compact central object. Given the large apparent velocity of the radio-emitting jets, by the time of our observations the Sams et al. feature would have moved more than 1'' from GRS 1915+105, and we can place a limit of K > 17.7 (95% confidence level) on any infrared emission in this region. We can thus place an upper limit of τ < 28 days on the radiative timescale of the feature, which is consistent with synchrotron jet emission.