2010ApJ...709L.163A

Query : 2010ApJ...709L.163A

2010ApJ...709L.163A - Astrophys. J., 709, L163-L167 (2010/February-1)

Discovery of variability in the very high energy γ-ray emission of 1ES 1218+304 with VERITAS.

ACCIARI V.A., ALIU E., BEILICKE M., BENBOW W., BOLTUCH D., BOTTCHER M., BRADBURY S.M., BUGAEV V., BYRUM K., CESARINI A., CIUPIK L., COGAN P., CUI W., DICKHERBER R., DUKE C., FALCONE A., FINLEY J.P., FINNEGAN G., FORTSON L., FURNISS A., GALANTE N., GALL D., GIBBS K., GUENETTE R., GILLANDERS G.H., GODAMBE S., GRUBE J., HANNA D., HUI C.M., HUMENSKY T.B., IMRAN A., KAARET P., KARLSSON N., KERTZMAN M., KIEDA D., KRAWCZYNSKI H., KRENNRICH F., LANG M.J., LEBOHEC S., MAIER G., McARTHUR S., McCANN A., MORIARTY P., NAGAI T., ONG R.A., OTTE A.N., PANDEL D., PERKINS J.S., PICHEL A., POHL M., QUINN J., RAGAN K., REYES L.C., REYNOLDS P.T., ROACHE E., ROSE H.J., SCHROEDTER M., SEMBROSKI G.H., SMITH A.W., STEELE D., SWORDY S.P., THEILING M., THIBADEAU S., VASSILIEV V.V., VINCENT S., WAKELY S.P., WEEKES T.C., WEINSTEIN A., WEISGARBER T. and WILLIAMS D.A.

Abstract (from CDS):

We present results from an intensive VERITAS monitoring campaign of the high-frequency peaked BL Lac object 1ES 1218+304 in 2008/2009. Although 1ES 1218+304 was detected previously by MAGIC and VERITAS at a persistent level of ∼6% of the Crab Nebula flux, the new VERITAS data reveal a prominent flare reaching ∼20% of the Crab. While very high energy (VHE) flares are quite common in many nearby blazars, the case of 1ES 1218+304 (redshift z = 0.182) is particularly interesting since it belongs to a group of blazars that exhibit unusually hard VHE spectra considering their redshifts. When correcting the measured spectra for absorption by the extragalactic background light, 1ES 1218+304 and a number of other blazars are found to have differential photon indices Γ≤ 1.5. The difficulty in modeling these hard spectral energy distributions in blazar jets has led to a range of theoretical γ-ray emission scenarios, one of which is strongly constrained by these new VERITAS observations. We consider the implications of the observed light curve of 1ES 1218+304, which shows day scale flux variations, for shock acceleration scenarios in relativistic jets, and in particular for the viability of kiloparsec-scale jet emission scenarios.

Abstract Copyright: ∼

Journal keyword(s): BL Lacertae objects: individual: 1ES 1218+304 = VER J1221+301 - galaxies: active - gamma rays: galaxies

Simbad objects: 6

Full paper

View the references in ADS

Number of rows : 6

N	Identifier	Otype	ICRS (J2000) RA	ICRS (J2000) DEC	Mag B	Mag V	Mag R	Sp type	#ref 1850 - 2026	#notes
1	RX J0232.8+2017	BLL	02 32 48.6148874688	+20 17 17.486717388		18.00	13.96	~	387	1
2	QSO B0347-121	BLL	03 49 23.1862105584	-11 59 27.366035532	18.74	18.2	17.46	~	245	1
3	RX J0710.5+5908	BLL	07 10 30.0683697888	+59 08 20.371772544	17.38	16.52	15.1	~	249	1
4	PMN J1103-2329	BLL	11 03 37.6150845072	-23 29 31.203773520	17.00	16.55	16.61	~	405	1
5	PG 1218+304	BLL	12 21 21.9426947832	+30 10 37.158534012	16.50	15.85	15.7	~	497	1
6	RX J1442.8+1200	BLL	14 42 48.2771008152	+12 00 40.348597716	18.34	17.63	15.2	~	189	1

To bookmark this query, right click on this link: simbad:objects in 2010ApJ...709L.163A and select 'bookmark this link' or equivalent in the popup menu