High-resolution, multifrequency radio observations of M82

Journal Article · Mon Sep 01 04:00:00 EDT 1975 · Astrophys. J., v. 200, no. 2, pp. 430-438

DOI:https://doi.org/10.1086/153807· OSTI ID:4149013

Kronberg, P P; Wilkinson, P N

A supersynthesis radio map of the 8085 MHz emission in M82 is presented. The radio structure is complex, and is dominated by a bright unresolved source which is unpolarized (<0.7%), becomes optically thick at $nu$approx. =650 MHz, and emits 65 percent of its 1666 MHz flux from within a region <1.2 pc in diameter. Nine other discrete radio components near the M82 nucleus have been isolated, and no other radio sources with surface brightness >5 K exist in the galaxy but outside the main radio source. An upper limit of 5 mJy can be set to any 8085 MHz radio emission from remnants, the brightest of which (source 41.9+58) is very recent (approximately-less-than150 years) and has brightness and size limits which are consistent with the $Sigma$-D relationship for known supernova remnants. The absence of a detectable linear polarization on all angular scales approximately-greater-than1'' suggests that the magnetic field in the M82 nucleus is highly tangled on all size scales down to approximately-less- than20 pc. (AIP)

• Research Organization: David Dunlap Observatory and Scarborough College, University of Toronto
• Sponsoring Organization: USDOE
• NSA Number: NSA-33-010108
• OSTI ID: 4149013
• Journal Information: Astrophys. J., v. 200, no. 2, pp. 430-438, Journal Name: Astrophys. J., v. 200, no. 2, pp. 430-438; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

*COSMIC RADIO SOURCES-- RESOLUTION
640103* --Physics Research--Astrophysics &amp; Cosmology--Quasi- Stellar
Radio &amp; X-Ray Sources
BRIGHTNESS
FREQUENCY DEPENDENCE
MAGNETIC FIELDS
N56300* --Physics (Astrophysics &amp; Cosmology)--Quasi-stellar
Radio &amp; X-Ray Sources
POLARIZATION
RADIOWAVE RADIATION
SUPERNOVA REMNANTS