6677( 7) - 10/18/96 11:07 - [ 0] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 6677 Version: 7 Check-in Date: 18-Oct-1996 11:03:02 1.Proposal Title: The Origin of the X-Ray Background: What are the faintest X-Ray Galaxies? ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle GALAXIES & CLUSTERS GO 6 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: IAN MCHARDY SOUTHAMPTON UNIVERSITY CoI: Andrew Newsam Physics Department, University of N Southampton CoI: Roberto Abraham Institute of Astronomy, Cambridge N CoI: Laurence Jones Goddard Space Flight Center N CoI: Michael Merrifield Physics Department, University of N Southampton ------------------------------------------------------------------------------------ 6. Abstract To determine the origin of the X-ray background (XRB) we have made the deepest optically identified (ROSAT) X-ray survey yet. At `bright' flux levels (ie 1 x 10**- 14 ergs/cm/s) QSOs dominate the survey but below 5 x 10**-15 ergs/cm/s our sample is dominated by a population of narrow emission line galaxies (NELGs), at typical redshifts of 0.2-0.5. The NELG source counts rise rapidly at faint X-ray fluxes making them a major contributor to the XRB. The X-ray spectra of the NELGs are hard, as is required for any major contributor to the XRB. Deep sub-arcsecond CFHT images indicate that the brightest (m_R < 18.5) systems are mainly interacting galaxies, probably spirals. Here we request WFC R-band images to determine the morphologies of the remaining systems which we cannot study from the ground to determine whether the remaining non-QSO XRB might be explained by emission from interacting or disturbed spirals. Disturbed systems are thought to be responsible for the faint blue galaxy population, IRAS starburst galaxies and the sub-mJy radio sources so our observations may have implications for the unification of all these populations, including X-ray NELGs. ------------------------------------------------------------------------------------ Observations Description ------------------------ THE SAMPLE The sample is statistically complete and well defined. The full sample consists of all 19 NELGs in our spectroscopically complete ROSAT deep survey. We remove from this list the 3 brightest NELGs (m_r < 18) which are reasonably studied from the ground. In order to keep the total HST observation time down we also remove the two faintest (m_r = 22.3 and 22.7) and most distant (both Z=0.58) objects from the sample leaving 13 NELGs in the magnitude range m_r 18.8 to 21.2. With one exception, all the remaining 13 have Z>0.2 Note that two NELGs lie within 1 arcmin and so can be observed simultaneously (so we list only 12 targets). Of these, in order to remain within the allocated time, we select the 10 with the brightest X-ray fluxes to give a statistically useful, flux-limited subset. FEASIBILITY AND OBSERVATION TIMES In the present proposal we choose the 814W filter to image all of our sample. As the mean redshift of our NELGs is 0.3, this gives us a rest-frame red image which will provide a good determination of the overall galaxy structure. One of us (Abraham) is heavily involved in the analysis of HST Medium Deep Survey images. Our experience there is that it is necessary to reach a surface brightness limit of approximately 24 mags/arcsec**2 in order to detect tidal debris and evidence of interactions. Our experience with MDS images also reveals that one needs to reach about that same surface brightness limit in order to reliably distinguish ellipticals from spirals on the basis of surface brightness profiles. Thus we take approximately 24 mags/arcsec**2 as our target surface brightness limit. Using the WWW exposure calculator we determine that, in order to reach approx. 24 mags/arcsec**2 per pixel (assuming Sbc spectra) in the WFC at a signal to noise of 2, we require total integration times in the 814W filter of 3500s. A S/N of 2 is low, but in the lower surface brightness regions we will probably average over a few pixels in order to determine the large scale structure of the galaxies. We note that 3500s is about 1.5 orbits. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: UPS Email: , ------------------------------------------------------------------------------------ 6677( 7) - 10/18/96 11:07 - [ 1] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 GAL- GALAXY,Seyfert,Starburs RA=13H 35M 25.20S +/- 0.01S, 2000 Z=0.235 V = 18.7+/-0.2 133525+38053 t DEC=38D 05' 36.4" +/- 0.1" V-R = 1.0+/-0.2 6 Comments: Rosat UK Deep Field object 36. 2 GAL- GALAXY,Seyfert,Starburs RA=13H 35M 04.35S +/- 0.02S, 2000 Z=0.368 V = 19.7+/-0.2 133502+37501 t DEC=37D 50' 02.1" +/- 0.2" V-R = 0.8+/-0.2 1 Comments: Rosat UK Deep Field object 42. Position is an offset so that Obj 47 is also included (ie at mid-point). 3 GAL- GALAXY,Seyfert,Starburs RA=13H 33M 29.02S +/- 0.01S, 2000 Z=0.385 V = 21.5+/-0.2 133329+37555 t DEC=37D 55' 57.8" +/- 0.1" V-R = 1.3+/-0.2 8 Comments: Rosat UK Deep Field object 43. 4 GAL- GALAXY,Seyfert,Starburs RA=13H 35M 00.20S +/- 0.01S, 2000 Z=0.558 V = 20.7+/-0.2 133500+37563 t,High z Gal DEC=37D 56' 33.2" +/- 0.1" V-R = 0.9+/-0.2 3 Comments: Rosat UK Deep Field object 67. 5 GAL- GALAXY,Seyfert,Starburs RA=13H 34M 08.82S +/- 0.01S, 2000 Z=0.304 V = 21.5+/-0.2 133409+37544 t DEC=37D 54' 43.5" +/- 0.1" V-R = 0.8+/-0.2 4 Comments: Rosat UK Deep Field object 85. 6 GAL- GALAXY,Seyfert,Starburs RA=13H 33M 53.80S +/- 0.01S, 2000 Z=0.590 V = 21.8+/-0.2 133354+38015 t,High z Gal DEC=38D 01' 56.0" +/- 0.1" V-R = 0.6+/-0.2 6 Comments: Rosat UK Deep Field object 93. 7 GAL- GALAXY,Seyfert,Starburs RA=13H 33M 46.07S +/- 0.01S, 2000 Z=0.061 V = 19.0+/-0.2 133346+38002 t DEC=38D 00' 25.3" +/- 0.1" V-R = 0.1+/-0.2 5 Comments: Rosat UK Deep Field object 94. 8 GAL- GALAXY,Seyfert,Starburs RA=13H 33M 31.07S +/- 0.01S, 2000 Z=0.200 V = 19.8+/-0.2 133331+37481 t DEC=37D 48' 09.8" +/- 0.1" V-R = 0.5+/-0.2 0 Comments: Rosat UK Deep Field object 103. 9 GAL- GALAXY,Seyfert,Starburs RA=13H 35M 18.67S +/- 0.01S, 2000 Z=0.310 V = 19.5+/-0.2 133519+37553 t DEC=37D 55' 31.6" +/- 0.1" V-R = 0.2+/-0.2 2 Comments: Rosat UK Deep Field object 121. 10 GAL- GALAXY,Seyfert,Starburs RA=13H 34M 57.67S +/- 0.01S, 2000 Z=0.250 V = 20.7+/-0.2 133458+37493 t DEC=37D 49' 34.2" +/- 0.1" V-R = 0.6+/-0.2 4 Comments: Rosat UK Deep Field object 127. 6677( 7) - 10/18/96 11:07 - [ 2] Visit: 01 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 GAL-133525+ WFPC2 IMAGE WF3-FIX F814W DITHER-TYPE=LINE, 1 600 S 380536 DITHER-LINE-STEPS=3, DITHER-LINE-SPACING=0.3300, CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ 6677( 7) - 10/18/96 11:07 - [ 3] Visit: 02 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 GAL-133502+ WFPC2 IMAGE WF3-FIX F814W DITHER-TYPE=BOX,CR-SPLIT=NO 1 1100 S 375011 Comments: Slightly uneven exposure on 4 dither positions would fill up the orbit. ------------------------------------------------------------------------------------------------------------------------------------ 6677( 7) - 10/18/96 11:07 - [ 4] Visit: 03 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 GAL-133329+ WFPC2 IMAGE WF3-FIX F814W DITHER-TYPE=BOX,CR-SPLIT=NO 1 1100 S 375558 Comments: Slightly uneven exposure on 4 dither positions would fill up the orbit. ------------------------------------------------------------------------------------------------------------------------------------ 6677( 7) - 10/18/96 11:07 - [ 5] Visit: 04 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 GAL-133500+ WFPC2 IMAGE WF3-FIX F814W DITHER-TYPE=BOX,CR-SPLIT=NO 1 1100 S 375633 Comments: Slightly uneven exposure on 4 dither positions would fill up the orbit. ------------------------------------------------------------------------------------------------------------------------------------ 6677( 7) - 10/18/96 11:07 - [ 6] Visit: 05 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 GAL-133409+ WFPC2 IMAGE WF3-FIX F814W DITHER-TYPE=BOX,CR-SPLIT=NO 1 1100 S 375444 Comments: Slightly uneven exposure on 4 dither positions would fill up the orbit. ------------------------------------------------------------------------------------------------------------------------------------ 6677( 7) - 10/18/96 11:07 - [ 7] Visit: 06 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 GAL-133354+ WFPC2 IMAGE WF3-FIX F814W DITHER-TYPE=BOX,CR-SPLIT=NO 1 1100 S 380156 Comments: Slightly uneven exposure on 4 dither positions would fill up the orbit. ------------------------------------------------------------------------------------------------------------------------------------ 6677( 7) - 10/18/96 11:07 - [ 8] Visit: 07 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 GAL-133346+ WFPC2 IMAGE WF3-FIX F814W DITHER-TYPE=LINE, 1 600 S 380025 DITHER-LINE-STEPS=3, DITHER-LINE-SPACING=0.3300, CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ 6677( 7) - 10/18/96 11:07 - [ 9] Visit: 08 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 GAL-133331+ WFPC2 IMAGE WF3-FIX F814W DITHER-TYPE=BOX,CR-SPLIT=NO 1 1100 S 374810 Comments: Slightly uneven exposure on 4 dither positions would fill up the orbit. ------------------------------------------------------------------------------------------------------------------------------------ 6677( 7) - 10/18/96 11:07 - [ 10] Visit: 09 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 GAL-133519+ WFPC2 IMAGE WF3-FIX F814W DITHER-TYPE=BOX,CR-SPLIT=NO 1 1100 S 375532 Comments: Slightly uneven exposure on 4 dither positions would fill up the orbit. ------------------------------------------------------------------------------------------------------------------------------------ 6677( 7) - 10/18/96 11:07 - [ 11] Visit: 10 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 GAL-133458+ WFPC2 IMAGE WF3-FIX F814W DITHER-TYPE=BOX,CR-SPLIT=NO 1 1100 S 374934 Comments: Slightly uneven exposure on 4 dither positions would fill up the orbit. ------------------------------------------------------------------------------------------------------------------------------------ 6677( 7) - 10/18/96 11:07 - [ 12] Summary Form for Proposal 6677 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters DITHER-TYPE=LINE DITHER-LINE-STEPS=3 DITHER-LINE-SPACING=0.3300 CR-SPLIT=NO DITHER-TYPE=BOX ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category GALAXIES & CLUSTERS ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F814W ------------------------------------------------------------------------------------------------------------------------------------ Target Names GAL-133525+380536 GAL-133502+375011 GAL-133329+375558 GAL-133500+375633 GAL-133409+375444 GAL-133354+380156 GAL-133346+380025 GAL-133331+374810 GAL-133519+375532 GAL-133458+374934 ------------------------------------------------------------------------------------------------------------------------------------