VLBI core fluxes and brightness temperatures

DOI

The 2017 observing campaign of the Event Horizon Telescope (EHT) delivered the first very long baseline interferometry (VLBI) images at the observing frequency of 230GHz, leading to a number of unique studies on black holes and relativistic jets from active galactic nuclei (AGN). In total, eighteen sources were observed, including the main science targets, Sgr A* and M 87, and various calibrators. Sixteen sources were AGN. We investigated the morphology of the sixteen AGN in the EHT 2017 data set, focusing on the properties of the VLBI cores: size, flux density, and brightness temperature. We studied their dependence on the observing frequency in order to compare it with the Blandford-Koenigl (BK) jet model. In particular, we aimed to study the signatures of jet acceleration and magnetic energy conversion. We modeled the source structure of seven AGN in the EHT 2017 data set using linearly polarized circular Gaussian components (1749+096, 1055+018, BL Lac, J0132-1654, J0006-0623, CTA 102, and 3C 454.3) and collected results for the other nine AGN from dedicated EHT publications, complemented by lower frequency data in the 2-86GHz range. Combining these data into a multifrequency EHT+ data set, we studied the dependences of the VLBI core component flux density, size, and brightness temperature on the frequency measured in the AGN host frame (and hence on the distance from the central black hole), characterizing them with power law fits. We compared the observations with the BK jet model and estimated the magnetic field strength dependence on the distance from the central black hole. Our observations spanning event horizon to parsec scales indicate a deviation from the standard BK model, particularly in the decrease of the brightness temperature with the observing frequency. Only some of the discrepancies may be alleviated by tweaking the model parameters or the jet collimation profile. Either bulk acceleration of the jet material, energy transfer from the magnetic field to the particles, or both are required to explain the observations. For our sample, we estimate a general radial dependence of the Doppler factor {delta}{prop.to}r^<=0.5^. This interpretation is consistent with a magnetically accelerated sub-parsec jet. We also estimate a steep decrease of the magnetic field strength with radius B{prop.to}r^-3^, hinting at jet acceleration or efficient magnetic energy dissipation.

Cone search capability for table J/A+A/695/A233/eht_2017 (Name, VLBI core S, Tb, Theta, z, B, d_BH, Lsyn)

Identifier
DOI http://doi.org/10.26093/cds/vizier.36950233
Source https://dc.g-vo.org/rr/q/lp/custom/CDS.VizieR/J/A+A/695/A233
Related Identifier https://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/695/A233
Related Identifier https://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/695/A233
Metadata Access http://dc.g-vo.org/rr/q/pmh/pubreg.xml?verb=GetRecord&metadataPrefix=oai_b2find&identifier=ivo://CDS.VizieR/J/A+A/695/A233
Provenance
Creator Roeder J.; Wielgus M.; Lobanov A.P.; Krichbaum T.P.; Nair D.G.; Lee S.-S.,Ros E.; Fish V.L.; Blackburn L.; Chan C.-K.; Issaoun S.; Janssen M.,Johnson M.D.; Doeleman S.S.; Bower G.C.; Crew G.B.; Tilanus R.P.J.,Savolainen T.; Impellizzeri C.M.V.; Alberdi A.; Baczko A.-K.; Gomez J.L.,Lu R.-S.; Paraschos G.F.; Traianou E.; Goddi C.; Kim D.; Lisakov M.,Kovalev Y.Y.; Voitsik P.A.; Sokolovsky K.V.; Akiyama K.; Albentosa-Ruiz E.,Alef W.; Algaba J.C.; Anantua R.; Asada K.; Azulay R.; Bach U.; Ball D.,Balokovic M.; Bandyopadhyay B.; Barrett J.; Bauboeck M.; Benson B.A.,Bintley D.; Blundell R.; Bouman K.L.; Bremer M.; Brinkerink C.D.,Brissenden R.; Britzen S.; Broderick A.E.; Broguiere D.; Bronzwaer T.,Bustamante S.; Byun D.-Y.; Carlstrom J.E.; Ceccobello C.; Chael A.,Chang D.O.; Chatterjee K.; Chatterjee S.; Chen M.-T.; Chen Y.; Cheng X.,Cho I.; Christian P.; Conroy N.S.; Conway J.E.; Cordes J.M.; Crawford T.M.,Cruz-Osorio A.; Cui Y.; Curd B.; Dahale R.; Davelaar J.; De Laurentis M.,Deane R.; Dempsey J.; Desvignes G.; Dexter J.; Dhruv V.; Dihingia I.K.,Taylor Dougall S.; Dzib S.A.; Eatough R.P.; Emami R.; Falcke H.; Farah J.,Fomalont E.; Ford H.A.; Foschi M.; Fraga-Encinas R.; Freeman W.T.,Friberg P.; Fromm C.M.; Fuentes A.; Galison P.; Gammie C.F.; Garcia R.,Gentaz O.; Georgiev B.; Gold R.; Gomez-Ruiz A.I.; Gu M.; Gurwell M.,Hada K.; Haggard D.; Haworth K.; Hecht M.H.; Hesper R.; Heumann D.; Ho L.C.,Ho P.; Honma M.; Huang C.-W.L.; Huang L.; Hughes D.H.; Ikeda S.; Inoue M.,James D.J.; Jannuzi B.T.; Jeter B.; Jiang W.; Jimenez-Rosales A.,Jorstad S.; Joshi A.V.; Jung T.; Karami M.; Karuppusamy R.; Kawashima T.,Keating G.K.; Kettenis M.; Kim D.-J.; Kim J.-Y.; Kim J.; Kino M.,Koay J.Y.; Kocherlakota P.; Kofuji Y.; Koyama S.; Kramer C.; Kramer J.A.,Kramer M.; Kuo C.-Y.; La Bella N.; Lauer T.R.; Lee D.; Leung P.K.; Levis A.,Li Z.; Lico R.; Lindahl G.; Lindqvist M.; Liu J.; Liu K.; Liuzzo E.,Lo W.-P.; Loinard L.; Lonsdale C.J.; Lowitz A.E.; MacDonald N.R.; Mao J.,Marchili N.; Markoff S.; Marrone D.P.; Marscher A.P.; Marti-Vidal I.,Matsushita S.; Matthews L.D.; Medeiros L.; Menten K.M.; Michalik D.,Mizuno I.; Mizuno Y.; Moran J.M.; Moriyama K.; Moscibrodzka M.; Mulaudzi W.,Mueller C.; Mueller H.; Mus A.; Musoke G.; Myserlis I.; Nadolski A.,Nagai H.; Nagar N.M.; Nakamura M.; Narayanan G.; Natarajan I.; Nathanail A.,Navarro Fuentes S.; Neilsen J.; Neri R.; Ni C.; Noutsos A.; Nowak M.A.,Oh J.; Okino H.; Olivares Sanchez H.R.; Ortiz-Leon G.N.; Oyama T.; Oezel F.,Palumbo D.C.M.; Park J.; Parsons H.; Patel N.; Pen U.-L.; Pesce D.W.,Pietu V.; Plambeck R.; PopStefanija A.; Porth O.; Poetzl F.M.; Prather B.,Preciado-Lopez J.A.; Principe G.; Psaltis D.; Pu H.-Y.; Ramakrishnan V.,Rao R.; Rawlings M.G.; Ricarte A.; Ripperda B.; Roelofs F.; Rogers A.,Romero-Canizales C.; Roshanineshat A.; Rottmann H.; Roy A.L.; Ruiz I.,Ruszczyk C.; Rygl K.L.J.; Sanchez S.; Sanchez-Argueelles D.,Sanchez-Portal M.; Sasada M.; Satapathy K.; Schloerb F.P.; Schonfeld J.,Schuster K.-F.; Shao L.; Shen Z.; Small D.; Won Sohn B.; SooHoo J.,Sosapanta Salas L.D.; Souccar K.; Stanway J.S.; Sun H.; Tazaki F.,Tetarenko A.J.; Tiede P.; Titus M.; Torne P.; Toscano T.; Trent T.,Trippe S.; Turk M.; van Bemmel I.; van Langevelde H.J.; van Rossum D.R.,Vos J.; Wagner J.; Ward-Thompson D.; Wardle J.; Washington J.E.,Weintroub J.; Wharton R.; Wiik K.; Witzel G.; Wondrak M.F.; Wong G.N.,Wu Q.; Yadlapalli N.; Yamaguchi P.; Yfantis A.; Yoon D.; Young A.; Young K.,Younsi Z.; Yu W.; Yuan F.; Yuan Y.-F.; Zensus J.A.; Zhang S.; Zhao G.-Y.,Zhao S.S. (the Event Horizon Telescope Collaboration)
Publisher CDS
Publication Year 2025
Rights https://cds.unistra.fr/vizier-org/licences_vizier.html
OpenAccess true
Contact CDS support team <cds-question(at)unistra.fr>
Representation
Resource Type Dataset; AstroObjects
Discipline Astrophysics and Astronomy; Galactic and extragalactic Astronomy; High Energy Astrophysics; Natural Sciences; Observational Astronomy; Physics; Stellar Astronomy