SIMBAD references

2011ApJ...740...95B - Astrophys. J., 740, 95 (2011/October-3)

Resolution of the compact radio continuum sources in Arp220.

BATEJAT F., CONWAY J.E., HURLEY R., PARRA R., DIAMOND P.J., LONSDALE C.J. and LONSDALE C.J.

Abstract (from CDS):

We present 2 cm and 3.6 cm wavelength very long baseline interferometry images of the compact radio continuum sources in the nearby ultra-luminous infrared galaxy Arp220. Based on their radio spectra and variability properties, we confirm these sources to be a mixture of supernovae (SNe) and supernova remnants (SNRs). Of the 17 detected sources we resolve 7 at both wavelengths. The SNe generally only have upper size limits. In contrast all the SNRs are resolved with diameters ≥ 0.27 pc. This size limit is consistent with them having just entered their Sedov phase while embedded in an interstellar medium (ISM) of density 104/cm3. These objects lie on the diameter-luminosity correlation for SNRs (and so also on the diameter-surface brightness relation) and extend these correlations to very small sources. The data are consistent with the relation L∝D –9/4. Revised equipartition arguments adjusted to a magnetic field to a relativistic particle energy density ratio of 1% combined with a reasonable synchrotron-emitting volume filling factor of 10% give estimated magnetic field strengths in the SNR shells of ∼15-50 mG. The SNR shell magnetic fields are unlikely to come from compression of ambient ISM fields and must instead be internally generated. We set an upper limit of 7 mG for the ISM magnetic field. The estimated energy in relativistic particles, 2%-20% of the explosion kinetic energy, is consistent with estimates from models that fit the IR-radio correlation in compact starburst galaxies.

Abstract Copyright:

Journal keyword(s): galaxies: individual: Arp220 - galaxies: starburst - ISM: supernova remnants

CDS comments: Calibrator J1532+2344 is not in SIMBAD.

Simbad objects: 29

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2023.02.04-16:25:57

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