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No Radio Emission from IGR J17419-2802 or GRS 1736-297

ATel #755; M. P. Rupen, A. J. Mioduszewski, V. Dhawan (NRAO)
on 1 Mar 2006; 22:17 UT
Credential Certification: Michael P. Rupen (mrupen@nrao.edu)

Subjects: Radio, X-ray, Black Hole, Neutron Star, Transient

Pursuant to the report of renewed X-ray activity in IGR J17419-2802 and GRS 1736-297 (ATel #744) on Feb. 19-20, both sources were observed with the Very Large Array (VLA) at 4.86 GHz on Feb. 26. In the case of IGR J17419-2802, there was no source within the revised Swift XRT error circle (ATel #745) with an rms of 95 microJy/beam; the min/max within that error circle were (-0.37, +0.32) mJy/beam. In the case of GRS 1736-297, there was no source within the 90 arcsecond GRS error circle (Pavlinksy et al. 1994 ApJ 425, 110; Cherepashchuk et al. 1994 A&A 289, 419), with an rms noise of 99 microJy/beam. Although the min/max within the latter error circle were +/-0.49 mJy/beam, bandwidth smearing in these high-resolution (A configuration) continuum observations leads to a more realistic limit of perhaps 1 mJy/beam on any radio emission.

We also observed IGR J17419-2802 in October 2005, with no detections. On Oct. 9th, the nominal flux density at the Swift location was 0.016 +/- 0.071 mJy/beam, at 8.46 GHz; on Oct. 10th, the nominal flux density was 0.034 +/- 0.099 mJy/beam, at 4.86 GHz. We note that the Swift X-ray detection (ATel #617) was made on Oct. 3rd, 2005.

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