BIG AGN & QUASAR PROJECTS FOR ROSAT

Martin Elvis
Harvard-Smithsonian Center for Astrophysics, elvis@cfa.harvard.edu

The following is the text from viewgraphs presented at the San Diego HEAD session on the ROSAT long-term observing plan.

Nearby AGN

Extended emission around Seyfert 1, 2s

About a dozen nearby AGN have deep ( 10 ks) HRI observations.
At least 1/2 of these show extended X-ray emission around the compact source.
For those which show extended emission, it is a major component: 20%-30% of HRI total count rate.
The extended X-ray emission appears related to extended optical/radio emission - but there are no clear correlations yet.
The extended emission may be aligned with jet axes.
The observations also show an excess of point-like sources near Seyferts.
OBSERVE: 50 nearby Seyferts at 25 ks each for 1.25 Ms.

Mini-AGN and LINERS

``Activity'' may be ubiquitous in galaxy nuclei.
- 1/3 of m<12.5 Shapley-Ames galaxies have LINER nuclei.
- 14% of same have Low Luminosity AGN (LLAGN, e.g., M 81) [Palomar survey].
Half of the LLAGN/LINERs in the Shapley-Ames catalog may have been missed (e.g., edge-on orientation).
No continuum flux is observed for these LLAGN/LINERS.
LLAGN are important to understanding the X-ray background and nature of the faintest X-ray sources.
The luminosity function of these objects is highly uncertain.
The HRI can separate the nucleus from bulge.
The Palomar sample has 486 galaxies. A well defined sub-set can be used for a ROSAT HRI survey.
10 ks is required to detect L erg s at 20 Mpc.
OBSERVE: 200 galaxies at 10 ks each for 2 Ms.

Dwarf Galaxies

Can dwarf galaxies harbor AGN? I.e., is there a lower limit to the galaxy mass in which a massive black hole can be found?
Are dwarf galaxies related to both quasar and galaxy formation processes?
Problems: a bright AGN would swamp a dwarf galaxy; a faint AGN ( erg s ) is hard to see optically.
Targeted survey of nearby, nucleated dwarfs: from Kraan-Kortweg & Tamman (1986)
OBSERVE: 50 dwarfs at 20 ks each for 1 Ms.

Rare and Distant AGN

Extreme examples of a class can illuminate their physics.
Extreme examples are ipso facto, rare.
Need survey volume to find them.
BUT: The ROSAT all-sky survey is wide angle, but shallow; pointed PSPC archive is deep, but narrow angle.
Therefore, we must target known examples from the radio and optical.

High Redshift Quasars

Aim: Study the evolution of emission mechanism and environment via , , and cut-offs.
Almost no radio-quiet z>2 quasars known in X-rays; none bright enough to get X-ray spectra.
OBSERVE: all 50 z>2 .AND. 17 QSOs at 20 ks each for 1 Ms.

High CSS and GPS Quasars

Compact (10-100 pc), lobe-dominated (non-blazar) quasars.
Are they confined by medium? X-ray cut-off; X-ray extent.
Approximately 10 cut-off examples.
Approximately 1 extended example. (out of approximately 3).
Approximately 75 CSS in 3CR (no GPS because of low frequency selection).
OBSERVE: at 5-10 ks each for 0.5 Ms.

Red Quasars

Mix of synchrotron cut-off, reddening, and quasars with no ``blue bump''?
Peculiar geometry? Nearly edge-on?
OBSERVE: 15% of 3CR, objects at 25 ks each (faint) for 1.25 Ms.

Damped L Absorbers

Lyman- absorption in quasars ( cm .)
Probable protogalaxies (e.g., Art Wolfe et al.) ( )
X-ray measurement of abundances (e.g., G. Madejski - A0235+164)
Few detections. Typically m=17-18.
OBSERVE: 20 DLA objects at 25 ks each for 0.5 Ms.

SUMMARY 7.5 Ms

Extended emission around Seyfert 1, 2s:
1.25 Ms
Mini-AGN & LINERS: 2 Ms
Dwarf galaxies: 1 Ms
High Redshift Quasars: 1 Ms
CSS & GPS Quasars: 0.5 Ms
Red Quasars: 1.25 Ms
Damped Lyman Systems: 0.5 Ms

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Mon Jun 3 11:52:11 EDT 1996