8011(  1) - 04/16/98 14:25  - [  1]

    PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS   ST ScI Use Only
                                                       ID:      8011
                                                       Version: 1
                                                       Check-in Date: 16-Apr-1998
                                                                      14:24:24

1.Proposal Title:
The Nature of Intrinsic Absorption in Seyfert 1 Galaxies
------------------------------------------------------------------------------------
2. Proposal For  3. Cycle
AR               7
------------------------------------------------------------------------------------
4. Investigators
                                                                                     Contact?
    PI: Steven Kraemer                    Catholic University of America
   CoI: Michael Crenshaw                  Catholic University of America                N

------------------------------------------------------------------------------------
5. Abstract

We have retrieved FOS and GHRS UV spectra of Seyfert 1 galaxies from the HST data
archive, to study a poorly understood component of active galaxies: intrinsic UV
absorption. We find that about 50\ 1 galaxies show absorption lines that are
intrinsic to the active nucleus, compared to previous estimates of 3 -- 10\ Recent
studies indicate that about half of all Seyfert 1 galaxies also exhibit X-ray ``warm
absorbers'', characterized by O VII and O V III absorption edges. The discovery of
frequent UV and X-ray absorption suggests that an important physical component has
been missing in our efforts to understand active galaxies. Our analysis of the HST
data shows that the absorbers are typically characterized by high ionization (C IV,
N V), blueshifts relative to systemic velocity (indicating outflow), multiple
kinematic components, broad widths (100 -- 300 km s^-1), and variability on time
scales of months or years. It appears that there is a one-to-one correspondence
between the presence of UV absorbers and X-ray warm absorbers. We request funds to
write the paper and publish our results, and to investigate two important issues. 1)
What is the global covering factor of the UV absorber? 2) What is the connection
between the UV and X-ray warm absorber?
------------------------------------------------------------------------------------
  Data Distribution

  Media:           ELECTRONIC
  Blocking Factor: 10
  Ship To:         PI_Address
  Ship Via:
  Email:
------------------------------------------------------------------------------------

                                                8011(  1) - 04/16/98 14:25  - [  2]

            Summary Form for Proposal  8011

  Item                         Used in this proposal
------------------------------------------------------------------------------------------------------------------------------------
  Proposal Category            AR
------------------------------------------------------------------------------------------------------------------------------------