A new look at the galaxies in the Xrays

1
A multiwavelength study of the low
luminosity MBH in NGC821 S.
Pellegrini (Astronomy Dept., Bologna, Italy), A.
Siemiginowska, G. Fabbiano, M. Elvis,
L. Greenhill, R. Soria, A. Baldi,
D.W. Kim (CfA, Cambdridge, MA, USA)

• The problem How is the activity of MBHs
  decreased/switched off after the bright AGN
  phase?
• turnes into a radiatively inefficient mode ( an
  outflow/jet) ?
• becomes intermittent ?
• remains AGN-like (just scaled-down) ?
• what consequences for the surrounding
  galaxy?
• NGC821 E6, LB2x1010 LB?, d24.1 Mpc,
  isolated, central MBH of MBH 8.5 x 107 M? from
  HST,
• regular and smooth in
  the optical, poor ISM content, typical (old
  and metal rich) stellar population
• Chandra (239 ksec)
• VLA (2 hrs at 3 freq.)
• Spitzer (725 sec)
• archival HST
• INT (R band)
• DISCUSSION (see also Pellegrini et al. 07,
  astro-ph/0701642)
• A nuclear source detected for the first time,
  with L(2-10 keV) / LEdd 10-8.

A coherent/general picture is needed !
Chandra ideal instrument

Chandra ACIS-S 0.3-6 keV
S2 is at the galactic center L(0.38 keV)
6.0 1038 erg s-1
VLA central 17x17 at 1.4 GHz (left) and 8.4
GHz (right) S2 detected, with F(1.4 GHz)127
?Jy, ?L? 1.2 x 1035 erg/s