2015ApJ...807..150A

Query : 2015ApJ...807..150A

2015ApJ...807..150A - Astrophys. J., 807, 150 (2015/July-2)

230 GHz VLBI observations of M87: event-horizon-scale structure during an enhanced very-high-energy gamma-ray state in 2012.

AKIYAMA K., LU R.-S., FISH V.L., DOELEMAN S.S., BRODERICK A.E., DEXTER J., HADA K., KINO M., NAGAI H., HONMA M., JOHNSON M.D., ALGABA J.C., ASADA K., BRINKERINK C., BLUNDELL R., BOWER G.C., CAPPALLO R., CREW G.B., DEXTER M., DZIB S.A., FREUND R., FRIBERG P., GURWELL M., HO P.T.P., INOUE M., KRICHBAUM T.P., LOINARD L., MacMAHON D., MARRONE D.P., MORAN J.M., NAKAMURA M., NAGAR N.M., ORTIZ-LEON G., PLAMBECK R., PRADEL N., PRIMIANI R.A., ROGERS A.E.E., ROY A.L., SOOHOO J., TAVARES J.-L., TILANUS R.P.J., TITUS M., WAGNER J., WEINTROUB J., YAMAGUCHI P., YOUNG K.H., ZENSUS A. and ZIURYS L.M.

Abstract (from CDS):

We report on 230 GHz (1.3 mm) very long baseline interferometry (VLBI) observations of M87 with the Event Horizon Telescope using antennas on Mauna Kea in Hawaii, Mt. Graham in Arizona, and Cedar Flat in California. For the first time, we have acquired 230 GHz VLBI interferometric phase information on M87 through measurement of the closure phase on the triangle of long baselines. Most of the measured closure phases are consistent with 0° as expected by physically motivated models for 230 GHz structure such as jet models and accretion disk models. The brightness temperature of the event-horizon-scale structure is K derived from the compact flux density of ∼1 Jy and the angular size of ∼40 ∼ 5.5, which is broadly consistent with the peak brightness of the radio cores at 1-86 GHz located within. Our observations occurred in the middle of an enhancement in very-high-energy (VHE)-ray flux, presumably originating in the vicinity of the central black hole. Our measurements, combined with results of multi-wavelength observations, favor a scenario in which the VHE region has an extended size of ∼20-60.

Abstract Copyright: ∼

Journal keyword(s): galaxies: active - galaxies: individual: M87 - galaxies: jets - radio continuum: galaxies - techniques: high angular resolution - techniques: interferometric

VizieR on-line data: <Available at CDS (J/ApJ/807/150): table2.dat table3.dat>

Simbad objects: 4

Full paper

View the references in ADS

Number of rows : 4

N	Identifier	Otype	ICRS (J2000) RA	ICRS (J2000) DEC	Mag U	Mag B	Mag V	Mag I	Sp type	#ref 1850 - 2024	#notes
1	NAME Knot in M87 Jet	PoG	12 30 49.355	+12 23 28.32					~	204	0
2	NAME M87 Jet	Rad	12 30 49.423	+12 23 28.04					~	253	1
3	M 87	AGN	12 30 49.42338414	+12 23 28.0436859	10.16	9.59	8.63	7.49	~	7206	3
4	NAME Sgr A*	X	17 45 40.03599	-29 00 28.1699					~	4394	3

To bookmark this query, right click on this link: simbad:objects in 2015ApJ...807..150A and select 'bookmark this link' or equivalent in the popup menu