2010ApJ...708.1254A

Query : 2010ApJ...708.1254A

2010ApJ...708.1254A - Astrophys. J., 708, 1254-1267 (2010/January-2)

Fermi large area telescope observations of the Crab pulsar and nebula.

ABDO A.A., ACKERMANN M., AJELLO M., ATWOOD W.B., AXELSSON M., BALDINI L., BALLET J., BARBIELLINI G., BARING M.G., BASTIERI D., BECHTOL K., BELLAZZINI R., BERENJI B., BLANDFORD R.D., BLOOM E.D., BONAMENTE E., BORGLAND A.W., BREGEON J., BREZ A., BRIGIDA M., BRUEL P., BURNETT T.H., CALIANDRO G.A., CAMERON R.A., CAMILO F., CARAVEO P.A., CASANDJIAN J.M., CECCHI C., CELIK O., CHEKHTMAN A., CHEUNG C.C., CHIANG J., CIPRINI S., CLAUS R., COGNARD I., COHEN-TANUGI J., COMINSKY L.R., CONRAD J., DERMER C.D., DE ANGELIS A., DE LUCA A., DE PALMA F., DIGEL S.W., DO COUTO E SILVA E., DRELL P.S., DUBOIS R., DUMORA D., ESPINOZA C., FARNIER C., FAVUZZI C., FEGAN S.J., FERRARA E.C., FOCKE W.B., FRAILIS M., FREIRE P.C.C., FUKAZAWA Y., FUNK S., FUSCO P., GARGANO F., GASPARRINI D., GEHRELS N., GERMANI S., GIAVITTO G., GIEBELS B., GIGLIETTO N., GIORDANO F., GLANZMAN T., GODFREY G., GRENIER I.A., GRONDIN M.-H., GROVE J.E., GUILLEMOT L., GUIRIEC S., HANABATA Y., HARDING A.K., HAYASHIDA M., HAYS E., HUGHES R.E., JOHANNESSON G., JOHNSON A.S., JOHNSON R.P., JOHNSON T.J., JOHNSON W.N., JOHNSTON S., KAMAE T., KATAGIRI H., KATAOKA J., KAWAI N., KERR M., KNODLSEDER J., KOCIAN M.L., KRAMER M., KUEHN F., KUSS M., LANDE J., LATRONICO L., LEE S.-H., LEMOINE-GOUMARD M., LONGO F., LOPARCO F., LOTT B., LOVELLETTE M.N., LUBRANO P., LYNE A.G., MAKEEV A., MARELLI M., MAZZIOTTA M.N., McENERY J.E., MEURER C., MICHELSON P.F., MITTHUMSIRI W., MIZUNO T., MOISEEV A.A., MONTE C., MONZANI M.E., MORETTI E., MORSELLI A., MOSKALENKO I.V., MURGIA S., NAKAMORI T., NOLAN P.L., NORRIS J.P., NOUTSOS A., NUSS E., OHSUGI T., OMODEI N., ORLANDO E., ORMES J.F., OZAKI M., PANEQUE D., PANETTA J.H., PARENT D., PELASSA V., PEPE M., PESCE-ROLLINS M., PIERBATTISTA M., PIRON F., PORTER T.A., RAINO S., RANDO R., RAY P.S., RAZZANO M., REIMER A., REIMER O., REPOSEUR T., RITZ S., ROCHESTER L.S., RODRIGUEZ A.Y., ROMANI R.W., ROTH M., RYDE F., SADROZINSKI H.F.-W., SANCHEZ D., SANDER A., SAZ PARKINSON P.M., SCARGLE J.D., SGRO C., SISKIND E.J., SMITH D.A., SMITH P.D., SPANDRE G., SPINELLI P., STAPPERS B.W., STRICKMAN M.S., SUSON D.J., TAJIMA H., TAKAHASHI H., TANAKA T., THAYER J.B., THAYER J.G., THEUREAU G., THOMPSON D.J., THORSETT S.E., TIBALDO L., TORRES D.F., TOSTI G., TRAMACERE A., UCHIYAMA Y., USHER T.L., VAN ETTEN A., VASILEIOU V., VILCHEZ N., VITALE V., WAITE A.P., WALLACE E., WANG P., WATTERS K., WELTEVREDE P., WINER B.L., WOOD K.S., YLINEN T. and ZIEGLER M.

Abstract (from CDS):

We report on γ-ray observations of the Crab Pulsar and Nebula using 8 months of survey data with the Fermi Large Area Telescope (LAT). The high quality light curve obtained using the ephemeris provided by the Nanay and Jodrell Bank radio telescopes shows two main peaks stable in phase with energy. The first γ-ray peak leads the radio main pulse by (281 ±12±21) µs, giving new constraints on the production site of non-thermal emission in pulsar magnetospheres. The first uncertainty is due to γ-ray statistics, and the second arises from the rotation parameters. The improved sensitivity and the unprecedented statistics afforded by the LAT enable precise measurement of the Crab Pulsar spectral parameters: cut-off energy at Ec = (5.8±0.5±1.2) GeV, spectral index of Γ = (1.97±0.02±0.06) and integral photon flux above 100 MeV of (2.09±0.03±0.18)x10–6/cm2/s. The first errors represent the statistical error on the fit parameters, while the second ones are the systematic uncertainties. Pulsed γ-ray photons are observed up to ∼ 20 GeV which precludes emission near the stellar surface, below altitudes of around 4-5 stellar radii in phase intervals encompassing the two main peaks. A detailed phase-resolved spectral analysis is also performed: the hardest emission from the Crab Pulsar comes from the bridge region between the two γ-ray peaks while the softest comes from the falling edge of the second peak. The spectrum of the nebula in the energy range 100 MeV-300 GeV is well described by the sum of two power laws of indices Γsync = (3.99±0.12±0.08) and ΓIC= (1.64±0.05±0.07), corresponding to the falling edge of the synchrotron and the rising edge of the inverse Compton (IC) components, respectively. This latter, which links up naturally with the spectral data points of Cherenkov experiments, is well reproduced via IC scattering from standard magnetohydrodynamic nebula models, and does not require any additional radiation mechanism.

Abstract Copyright: ∼

Journal keyword(s): gamma rays: observations - ISM: individual: Crab Nebula - pulsars: individual: Crab - supernova remnants

Simbad objects: 7

goto Full paper

goto View the references in ADS

Number of rows : 7
N Identifier Otype ICRS (J2000)
RA 		ICRS (J2000)
DEC 		Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2026 		#notes
1 SNR G119.5+10.2 SNR 00 06.6 +72 47           ~ 268 1
2 M 1 SNR 05 34 31.8 +22 01 03           ~ 6516 1
3 V* CM Tau Psr 05 34 31.9474694616 +22 00 52.153698024           ~ 5476 0
4 PSR J0633+1746 Psr 06 33 54.153 +17 46 12.91           ~ 1308 0
5 NAME Vela SNR 08 34.0 -45 50           ~ 1331 2
6 NAME Vela Pulsar Psr 08 35 20.65525 -45 10 35.1545     15.10     ~ 2446 1
7 PSR J2021+3651 Psr 20 21 05.40 +36 51 04.5           ~ 218 1

To bookmark this query, right click on this link: simbad:objects in 2010ApJ...708.1254A and select 'bookmark this link' or equivalent in the popup menu