NASA/IPAC EXTRAGALACTIC DATABASE
Date and Time of the Query: 2019-06-15 T21:14:39 PDT
Help | Comment | NED Home

For refcode 2018ApJ...862...20M:
Retrieve 2 NED objects in this reference.
Please click here for ADS abstract

NED Abstract

Copyright by American Astronomical Society. Reproduced by permission
2018ApJ...862...20M A New Detection of Extragalactic Anomalous Microwave Emission in a Compact, Optically Faint Region of NGC 4725 Murphy, E. J.; Linden, S. T.; Dong, D.; Hensley, B. S.; Momjian, E.; Helou, G.; Evans, A. S. Abstract. We discuss the nature of a discrete, compact radio source (NGC 4725 B) located ~1.9 kpc from the nucleus in the nearby star-forming galaxy NGC 4725, which we believe to be a new detection of extragalactic anomalous microwave emission (AME). Based on detections at 3, 15, 22, 33, and 44 GHz, NGC 4725 B is a microjansky radio source peaking at ~33 GHz. While the source is not identified in optical (BVRI) photometry, we detect counterparts in the midinfrared Spitzer/IRAC bands (3.6, 4.5, 5.8, 8.0 micron) that appear to be associated with dust emission in the central region of NGC 4725. Consequently, we conclude that NGC 4725 B is a new detection of AME and is very similar to a recent detection of AME in an outer-disk star-forming region in NGC 6946. We find that models of electric dipole emission from rapidly rotating ultra-small grains are able to reproduce the radio spectrum for reasonable interstellar medium conditions. Given the lack of an optical counterpart and the shape of the radio spectrum, NGC 4725 B appears consistent with a nascent star-forming region in which young (<~3 Myr) massive stars are still highly enshrouded by their natal cocoons of gas and dust with insufficient supernovae occurring to produce a measurable amount of synchrotron emission. Key words: dust, extinction, galaxies: individual: NGC 4725, H II regions, radio continuum: general, stars: formation
Retrieve 2 NED objects in this reference.
Please click here for ADS abstract

Back to NED Home