Poчetna     Да почнемо     To Survive in the Universe    
Inhabited Sky
    News@Sky     Астро Фотографије     Колекција     Форум     Blog New!     FAQ(Често постављана питања     Штампа     Улогуј се  

HD 190857


Contingut

Imatges

Carregar la teva Imatge

DSS Images   Other Images


Articles Relacionats

Chandra observations of the X-ray environment of BL Lacs
We present Chandra observations of the X-ray environment of a sample of6 BL Lacertae objects. The improved sensitivity of the ACIS experimentallows us to separate the core X-ray emission from the contribution ofdiffuse emission from the host galaxy/cluster scales. Within the short(2-6 ks) ACIS exposures, we find evidence for diffuse X-ray emission in3 sources (BL Lac, PKS 0548-322, and PKS 2005-489). The diffuse emissioncan be modeled with a King profile with beta ~ 0.3-0.6, core radiirc ~ 15-28 kpc, and 0.4-5 keV luminosities in the range1041-1042 erg s-1. In the remaining 3sources, one (3C 371) has a radial profile entirely consistent with anunresolved source, while two (1ES 2344+514 and 1ES 2321+419) showevidence for weak diffuse emission on kpc scales. These results supportcurrent models for radio-loud AGN unifying BL Lacs and FRI radiogalaxies through the orientation of their jets. In PKS 0548-322 and PKS2005-489, we also find evidence for diffuse emission on cluster scales,although the spatial properties of this emission are not constrained.The temperature (kT ~ 3-5 keV) and luminosity (L0.4-5 keV ~1042 erg s-1) of the cluster gas are typical ofnormal clusters. Interestingly, these are the two brightest sources ofthe sample, suggesting a link between environment and nuclear activity.

Micrometer measures of 401 double stars.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1972AJ.....77..878W&db_key=AST

Enviar un nou article


Enllaços Relacionats

  • - No s'ha trobat enllaços -
Enviar un nou enllaç


Membre dels grups següents:


Dades d'Observació i Astrometria

Constel·lació:Telescopium
Ascensió Recta:20h09m07.12s
Declinació:-48°55'34.4"
Magnitud Aparent:10.139
Moviment propi RA:13.9
Moviment propi Dec:12.7
B-T magnitude:10.912
V-T magnitude:10.203

Catàlegs i designacions:
Noms Propis   (Edit)
HD 1989HD 190857
TYCHO-2 2000TYC 8400-1010-1
USNO-A2.0USNO-A2 0375-38531345
HIPHIP 99275

→ Sol·licitar més catàlegs i designacions de VizieR