2003A&A...406L...9A

Query : 2003A&A...406L...9A

2003A&A...406L...9A - Astronomy and Astrophysics, volume 406, L9-13 (2003/7-4)

Detection of TeV gamma-rays from the BL Lac 1ES1959+650 in its low states and during a major outburst in 2002.

AHARONIAN F., AKHPERJANIAN A., BEILICKE M., BERNLOEHR K., BOERST H.-G., BOJAHR H., BOLZ O., COARASA T., CONTRERAS J.L., CORTINA J., DENNINGHOFF S., FONSECA M.V., GIRMA M., GOETTING N., HEINZELMANN G., HERMANN G., HEUSLER A., HOFMANN W., HORNS D., JUNG I., KANKANYAN R., KESTEL M., KOHNLE A., KONOPELKO A., KORNMEYER H., KRANICH D., LAMPEITL H., LOPEZ M., LORENZ E., LUCARELLI F., MANG O., MEYER H., MIRZOYAN R., MORALEJO A., ONA-WILHELMI E., PANTER M., PLYASHESHNIKOV A., PUEHLHOFER G., DE LOS REYES R., RHODE W., RIPKEN J., ROBRADE J., ROWELL G., SAHAKIAN V., SAMORSKI M., SCHILLING M., SIEMS M., SOBZYNSKA D., STAMM W., TLUCZYKONT M., VITALE V., VOELK H.J., WIEDNER C.A. and WITTEK W.

Abstract (from CDS):

TeV γ-rays from the BL Lac object 1ES1959+650 have been measured during the years 2000 and 2001 with a significance of 5.2σ at a value of 5.3% of the Crab flux and in May 2002 during strong outbursts with >23σ at a flux level of up to 2.2 Crab, making 1ES1959+650 the TeV Blazar with the third best event statistics. The deep observation of 197.4h has been performed with the HEGRA stereoscopic system of 5 imaging atmospheric Cherenkov telescopes (IACT system). 1ES1959+650 is located at a redshift of z=0.047, providing an intermediate distance between the nearby Blazars Mkn 421 and Mkn 501, and the much more distant object H1426+428. This makes 1ES1959+650 an important member of the class of TeV Blazars in view of the absorption of TeV photons by the diffuse extragalactic background radiation (DEBRA). The differential energy spectrum of 1ES1959+650 during the flares can be fitted by a power law with a spectral index of 2.83±0.14_stat±0.08_sys or by a power law with an exponential cut-off at (4.2^+0.8_-0.6 stat_±0.9sys_)TeV and a spectral index of 1.83±0.15_stat±0.08_sys. The low state differential energy spectrum obtained with lower statistics can be described by a pure power law with a spectral index of 3.18±0.17_stat±0.08_sys.

Abstract Copyright: ∼

Journal keyword(s): γ-rays: observations - BL Lacertae objects: individual: 1ES 1959+650

VizieR on-line data: <Available at CDS (J/A+A/406/L9): table4.dat>

Simbad objects: 5

Full paper

View the references in ADS

Number of rows : 5

N	Identifier	Otype	ICRS (J2000) RA	ICRS (J2000) DEC	Mag U	Mag B	Mag V	Mag R	Sp type	#ref 1850 - 2024	#notes
1	Mrk 421	BLL	11 04 27.3140835504	+38 12 31.798495872		13.50	12.90	8.31	~	2675	1
2	QSO B1426+428	BLL	14 28 32.6090008440	+42 40 21.048123396		16.95	16.45	14.4	~	519	2
3	7C 165211.80+395026.00	BLL	16 53 52.21668403	+39 45 36.6088754	14.09	14.15	13.29	8.26	~	2162	2
4	QSO B1959+650	BLL	19 59 59.8520303688	+65 08 54.652536492			12.8	11.21	~	626	2
5	QSO B2155-304	BLL	21 58 52.0652249880	-30 13 32.118447792		13.36	13.09	12.62	~	1733	1

To bookmark this query, right click on this link: simbad:objects in 2003A&A...406L...9A and select 'bookmark this link' or equivalent in the popup menu