@misc{morabito2022identifying,
  abstract = {Identifying active galactic nuclei (AGN) and isolating their contribution to
a galaxy's energy budget is crucial for studying the co-evolution of AGN and
their host galaxies. Brightness temperature ($T_b$) measurements from
high-resolution radio observations at GHz frequencies are widely used to
identify AGN. Here we investigate using new sub-arcsecond imaging at 144 MHz
with the International LOFAR Telescope to identify AGN using $T_b$ in the
Lockman Hole field. We use ancillary data to validate the 940 AGN
identifications, finding 83 percent of sources have AGN classifications from
SED fitting and/or photometric identifications, yielding 160 new AGN
identifications. Considering the multi-wavelength classifications, brightness
temperature criteria select over half of radio-excess sources, 32 percent of
sources classified as radio-quiet AGN, and 20 percent of sources classified as
star-forming galaxies. Infrared colour-colour plots and comparison with what we
would expect to detect based on peak brightness in 6 arcsec LOFAR maps, imply
that the star-forming galaxies and sources at low flux densities have a mixture
of star-formation and AGN activity. We separate the radio emission from
star-formation and AGN in unresolved, $T_b$-identified AGN with no significant
radio excess and find the AGN comprises $0.49\pm 0.16$ of the radio luminosity.
Overall the non-radio excess AGN show evidence for having a variety of
different radio emission mechanisms, which can provide different pathways for
AGN and galaxy co-evolution. This validation of AGN identification using
brightness temperature at low frequencies opens the possibility for securely
selecting AGN samples where ancillary data is inadequate.},
  added-at = {2022-07-28T10:58:41.000+0200},
  author = {Morabito, Leah K. and Sweijen, F. and Radcliffe, J. F. and Best, P. N. and Kondapally, Rohit and Bondi, Marco and Bonato, Matteo and Duncan, K. J. and Prandoni, Isabella and Shimwell, T. W. and Williams, W. L. and van Weeren, R. J. and Conway, J. E. and Rivera, G. Calistro},
  biburl = {https://www.bibsonomy.org/bibtex/242addf45d77084fb1783c19d8c8db1e4/gpkulkarni},
  description = {Identifying active galactic nuclei via brightness temperature with sub-arcsecond International LOFAR Telescope observations},
  interhash = {2c7d9a92675a442bc0e55abf26765730},
  intrahash = {42addf45d77084fb1783c19d8c8db1e4},
  keywords = {library},
  note = {cite arxiv:2207.13096Comment: Accepted for publication in MNRAS. 19 pages, 15 figures, 2 tables},
  timestamp = {2022-07-28T10:58:41.000+0200},
  title = {Identifying active galactic nuclei via brightness temperature with
  sub-arcsecond International LOFAR Telescope observations},
  url = {http://arxiv.org/abs/2207.13096},
  year = 2022
}

{"_id":"CESFnFPsHoYEdk78q","bibbaseid":"morabito-sweijen-radcliffe-best-kondapally-bondi-bonato-duncan-etal-identifyingactivegalacticnucleiviabrightnesstemperaturewithsubarcsecondinternationallofartelescopeobservations-2022","author_short":["Morabito, L. K.","Sweijen, F.","Radcliffe, J. F.","Best, P. N.","Kondapally, R.","Bondi, M.","Bonato, M.","Duncan, K. J.","Prandoni, I.","Shimwell, T. W.","Williams, W. L.","van Weeren, R. J.","Conway, J. E.","Rivera, G. C."],"bibdata":{"bibtype":"misc","type":"misc","abstract":"Identifying active galactic nuclei (AGN) and isolating their contribution to a galaxy's energy budget is crucial for studying the co-evolution of AGN and their host galaxies. Brightness temperature ($T_b$) measurements from high-resolution radio observations at GHz frequencies are widely used to identify AGN. Here we investigate using new sub-arcsecond imaging at 144 MHz with the International LOFAR Telescope to identify AGN using $T_b$ in the Lockman Hole field. We use ancillary data to validate the 940 AGN identifications, finding 83 percent of sources have AGN classifications from SED fitting and/or photometric identifications, yielding 160 new AGN identifications. Considering the multi-wavelength classifications, brightness temperature criteria select over half of radio-excess sources, 32 percent of sources classified as radio-quiet AGN, and 20 percent of sources classified as star-forming galaxies. Infrared colour-colour plots and comparison with what we would expect to detect based on peak brightness in 6 arcsec LOFAR maps, imply that the star-forming galaxies and sources at low flux densities have a mixture of star-formation and AGN activity. We separate the radio emission from star-formation and AGN in unresolved, $T_b$-identified AGN with no significant radio excess and find the AGN comprises $0.49± 0.16$ of the radio luminosity. Overall the non-radio excess AGN show evidence for having a variety of different radio emission mechanisms, which can provide different pathways for AGN and galaxy co-evolution. This validation of AGN identification using brightness temperature at low frequencies opens the possibility for securely selecting AGN samples where ancillary data is inadequate.","added-at":"2022-07-28T10:58:41.000+0200","author":[{"propositions":[],"lastnames":["Morabito"],"firstnames":["Leah","K."],"suffixes":[]},{"propositions":[],"lastnames":["Sweijen"],"firstnames":["F."],"suffixes":[]},{"propositions":[],"lastnames":["Radcliffe"],"firstnames":["J.","F."],"suffixes":[]},{"propositions":[],"lastnames":["Best"],"firstnames":["P.","N."],"suffixes":[]},{"propositions":[],"lastnames":["Kondapally"],"firstnames":["Rohit"],"suffixes":[]},{"propositions":[],"lastnames":["Bondi"],"firstnames":["Marco"],"suffixes":[]},{"propositions":[],"lastnames":["Bonato"],"firstnames":["Matteo"],"suffixes":[]},{"propositions":[],"lastnames":["Duncan"],"firstnames":["K.","J."],"suffixes":[]},{"propositions":[],"lastnames":["Prandoni"],"firstnames":["Isabella"],"suffixes":[]},{"propositions":[],"lastnames":["Shimwell"],"firstnames":["T.","W."],"suffixes":[]},{"propositions":[],"lastnames":["Williams"],"firstnames":["W.","L."],"suffixes":[]},{"propositions":["van"],"lastnames":["Weeren"],"firstnames":["R.","J."],"suffixes":[]},{"propositions":[],"lastnames":["Conway"],"firstnames":["J.","E."],"suffixes":[]},{"propositions":[],"lastnames":["Rivera"],"firstnames":["G.","Calistro"],"suffixes":[]}],"biburl":"https://www.bibsonomy.org/bibtex/242addf45d77084fb1783c19d8c8db1e4/gpkulkarni","description":"Identifying active galactic nuclei via brightness temperature with sub-arcsecond International LOFAR Telescope observations","interhash":"2c7d9a92675a442bc0e55abf26765730","intrahash":"42addf45d77084fb1783c19d8c8db1e4","keywords":"library","note":"cite arxiv:2207.13096Comment: Accepted for publication in MNRAS. 19 pages, 15 figures, 2 tables","timestamp":"2022-07-28T10:58:41.000+0200","title":"Identifying active galactic nuclei via brightness temperature with sub-arcsecond International LOFAR Telescope observations","url":"http://arxiv.org/abs/2207.13096","year":"2022","bibtex":"@misc{morabito2022identifying,\n abstract = {Identifying active galactic nuclei (AGN) and isolating their contribution to\r\na galaxy's energy budget is crucial for studying the co-evolution of AGN and\r\ntheir host galaxies. Brightness temperature ($T_b$) measurements from\r\nhigh-resolution radio observations at GHz frequencies are widely used to\r\nidentify AGN. Here we investigate using new sub-arcsecond imaging at 144 MHz\r\nwith the International LOFAR Telescope to identify AGN using $T_b$ in the\r\nLockman Hole field. We use ancillary data to validate the 940 AGN\r\nidentifications, finding 83 percent of sources have AGN classifications from\r\nSED fitting and/or photometric identifications, yielding 160 new AGN\r\nidentifications. Considering the multi-wavelength classifications, brightness\r\ntemperature criteria select over half of radio-excess sources, 32 percent of\r\nsources classified as radio-quiet AGN, and 20 percent of sources classified as\r\nstar-forming galaxies. Infrared colour-colour plots and comparison with what we\r\nwould expect to detect based on peak brightness in 6 arcsec LOFAR maps, imply\r\nthat the star-forming galaxies and sources at low flux densities have a mixture\r\nof star-formation and AGN activity. We separate the radio emission from\r\nstar-formation and AGN in unresolved, $T_b$-identified AGN with no significant\r\nradio excess and find the AGN comprises $0.49\\pm 0.16$ of the radio luminosity.\r\nOverall the non-radio excess AGN show evidence for having a variety of\r\ndifferent radio emission mechanisms, which can provide different pathways for\r\nAGN and galaxy co-evolution. This validation of AGN identification using\r\nbrightness temperature at low frequencies opens the possibility for securely\r\nselecting AGN samples where ancillary data is inadequate.},\n added-at = {2022-07-28T10:58:41.000+0200},\n author = {Morabito, Leah K. and Sweijen, F. and Radcliffe, J. F. and Best, P. N. and Kondapally, Rohit and Bondi, Marco and Bonato, Matteo and Duncan, K. J. and Prandoni, Isabella and Shimwell, T. W. and Williams, W. L. and van Weeren, R. J. and Conway, J. E. and Rivera, G. Calistro},\n biburl = {https://www.bibsonomy.org/bibtex/242addf45d77084fb1783c19d8c8db1e4/gpkulkarni},\n description = {Identifying active galactic nuclei via brightness temperature with sub-arcsecond International LOFAR Telescope observations},\n interhash = {2c7d9a92675a442bc0e55abf26765730},\n intrahash = {42addf45d77084fb1783c19d8c8db1e4},\n keywords = {library},\n note = {cite arxiv:2207.13096Comment: Accepted for publication in MNRAS. 19 pages, 15 figures, 2 tables},\n timestamp = {2022-07-28T10:58:41.000+0200},\n title = {Identifying active galactic nuclei via brightness temperature with\r\n sub-arcsecond International LOFAR Telescope observations},\n url = {http://arxiv.org/abs/2207.13096},\n year = 2022\n}\n\n","author_short":["Morabito, L. K.","Sweijen, F.","Radcliffe, J. 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