Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.atnf.csiro.au/research/cena/documents/presentations/israel.pdf Дата изменения: Thu Jul 16 04:36:59 2009 Дата индексирования: Fri Nov 27 08:00:02 2009 Кодировка: Поисковые слова: dust disk

· Emission and Absorption of · Circumnuclear Molecular Gas in CENTAURUS A
Frank Israel, Sterrewacht Leiden, the Netherlands.


Heart of darkness ...
· · · · · Recent merger elliptical and small spiral Dark band is thin tilted disk dust and gas Precessing jets from SMBH 5.5 x 107 MO Submilliarcsec nucleus AV = 1216 mag Ongoing Accretion?





CEN A JCMTSCUBA 850 MICRON


Centaurus A Core SED
Meisenheimer et al (2007)



nucleus strong at mm wavelengths


12

CO(32) Line and Continuum

JCMT 345 GHz


CEN A CO(21) SMA
12

Espada et al. (2009)


20" (350 pc) CND rapid rotation V=200 km/s

CEN A Central Molecular Gas


Cen A Absorption Line Detections
· · · · · · · · · · 1970 Roberts HI 197179 Whiteoak & Gardner 198690 Seaquist & Bell H2CO, OH, C3H2, NH3

·



199003 Israel ea, Eckart ea, Wiklind & Combes CO, 13CO, HCO+, HCN, HNC, H13CN CS, CN, etc ...




Israel et al. (1990, 1991) SEST


Cen A Nuclear Absorption Lines
· · · · · · · · · · · · · · · · · a. strong narrow lines near systemic velocity b. blueshifted, weak broad absorption limited vel range c. redshifted, broad absorption, wide vel range, spikes


Israel ) (1992 SEST


J=10 12CO SEST J=32 12CO JCMT


A Problem of Decomposition ....
· · · · · · · · · · · continuum narrow emission dark band wide emission CND wide and deep absorption both s


left: SEST beam right: SMA beam


VLA HI Sarma et al 2002


... and a problematical lineofsight off by 0.30.5 pc!


HI CS 21/32

·

· HCO+ · · 10/32


Condition of the gas in Cen A
· · · · · · Central absorption lines and redshifted absorption both have 1. high column density N(H2 )=1021 1022 cm 2. low excitation T=1020 K 3. differential abundances
2


smooth: J=10 HCO+ SEST histogram: [CI] APEX Molecular dissociation?


HCO+ optical depth variation ~10% in 10 years

Cen A VLBI Tingay et al. 1998






Cen A 12CO J=10 SEST J=21 SEST J=32 JCMT





Charmandaris et al (2002)