8299( 5) - 01/18/00 11:49 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 8299 Version: 5 Check-in Date: 18-Jan-2000 11:48:45 1.Proposal Title: Mapping the Dynamics of the quasar 3C 48 ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 8 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Walter Jaffe Sterrewacht Leiden CoI: Eleni Chatzichristou Leiden Observatory N CoI: Dr. Christian Vanderriest Paris-Meudon Observatory N ------------------------------------------------------------------------------------ 5. Abstract In quasars and radio galaxies there is a relation between the properties of the radio source and those of the (optical) line-emitting gas. Compact steep-spectrum (CSS) radio sources often show disturbed kinematics of the interstellar gas coupled to associated radio components, providing evidence for gas outflow. The interaction between radio jets and the host galaxy ISM may be responsible for the jet confinement to small scales and can contribute to the ionization of the medium and lead to star formation. Detailed study of the circumnuclear region is essential in understanding the processes that drive the kinematics, physical conditions and morphology of the line emitting gas. The archetypical, nearby (z=0.37) quasar 3C 48 is an unusual CSS radio source with excess far-IR emission, whose one-sided radio jet is aligned with the extended ionized emission and a putative second nucleus (3C 48A). The radio morphology and our ground based integral field spectroscopy of 3C 48 sugge st the jet is interacting with its immediate environment. 3C 48, because of its high AGN luminosity and proximity, is a good candidate to search for kinematic signatures of the radio jet-gas coupling and/or of a recent interaction. We propose STIS long slit spectroscopy in several slit positions to map the kinematics and physical conditions of the extended emission line gas and their relations to near- nuclear star forming regions found in existing HST images. ------------------------------------------------------------------------------------ 8299( 5) - 01/18/00 11:49 - [ 2] Observations Description ------------------------ We propose to map 3C 48 using STIS CCD long-slit spectroscopy in intermediate- resolution first-order mode. We will use the G750M grating, which provides a large spectral range to detect the most useful emission lines and high spectral resolution so as to resolve multiple velocity components in the line profiles. We will use the 52arcsec*0.2" slit, which provides a good compromise between resolution and throughput, in a North-South orientation (PA=0degrees). We will take five series of exposures, each stepped relative to the next by 0.3'' in the direction perpendicular to the slit, with the setting covering the spectral region 6482-7054Angstrom, in order to map the gas kinematics by means of the OIII_4959, 5007 narrow emission lines. We will also use the setting covering the spectral region 8539-9111Angstrom, but only for the central slit position, passing through the quasar nucleus. This will allow detection of the OI_6300, HAlpha and NII_6548, 6583 emission lines at high S/ N. Note that we have increased the step size between slit positions compared to our Phase I proposal (0.2''). This is because the TAC only allocated one half of our requested exposures, and a larger spacing is needed to cover the emssion line area. Based on previous observations of the OIII_4959, 5007 emission lines, taken at the CFHT with a seeing of sim0.7" (Chatzichristou Etal, 1998), we have calculated S/N ratios and integration times for the various settings described above. The mean OIII_5007 surface brightness within the nuclear 1.1 arcsec^2 region is sim1.5*10^-15 ergs cm^-2 sec^-1 AA^-1 arcsec^-2 and that of an extended emission line cloud sim1.8" north of the nucleus is sim0.13*10^-15 ergs cm^-2 sec^-1 AA^-1 arcsec^-2. The surface brightness in the region of 3C 48A (sim1.3'' NE from the nucleus) is intermediate between these two. An integration time of 2000 sec, which we have calculated to be approximately the available time for scientific exposure at the object's declination and allowing for overhead time, yields a S/N per resolution element of ~12 for the nuclear region, but only ~1.4 for the extended emission cloud. By doubling the e xp osure time, the S/N per resolution element for the emission-line cloud becomes ~2.5. This is good enough, because in this case the S/N on the integrated emission line (FWHMapprox17Angstrom) is ~10. We repeated the same calculations at the HAlpha wavelength, using our observed fluxes for the HBeta line and assuming a standard HAlpha/HBeta ratio of 3.1. An integration time of 4000 sec yields a S/N per resolution element of ~ 12.3 for the nuclear region and ~3.4 for the extended emission line cloud. We thus conclude that 4000 sec (two orbits) total integration time is needed at each position and we will use CR- SPLIT=2~33 minutes per orbit. Requiring five slit positions for the short wavelength tilt and 1 position for the long wavelength tilt, the total allocated number of orbits (12) is matched. We need to allow for overhead time for the guide star (re- )acquisition (6-7 minutes) per orbit, the target acquisition for the first orbit (calculated to be ~8.5 minutes for the bright q uasar nucleus), 5 minutes for the first orbit of each of the two grating settings, 0.33 minutes for each target offset to the initial position, 1 minute overhead to move the aperture wheel for the first orbit, 1 minute for exposure overhead (CR-SPLIT=2) per orbit and 2 minutes for fringe flats per orbit when using the long wavelength grating setting. Thus, the total overhead time ranges between 7 and 22 minutes per orbit. Assuming a visibility period of 54 min for each orbit, appropriate for the declination of 3C 48, the scientific exposure times range between 32 and 47 minutes per orbit which is, as calculated above, appropriate for reaching the required S/N ratio. Real Time Justification ----------------------- Calibration Justification ------------------------- Eleni Chatzichristou Leiden Observatory Additional Comments ------------------- ------------------------------------------------------------------------------------ 8299( 5) - 01/18/00 11:49 - [ 3] Data Distribution Paper Products: YES Media: DAT Blocking Factor: 10 Ship To: PI_Address Ship Via: Email: ------------------------------------------------------------------------------------ 8299( 5) - 01/18/00 11:49 - [ 4] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 3C48 GALAXY, QSO RA=01H 37M 41.28S +/- 0.015S, J2000 Z=0.37 V = +16.5+/-0.2 DEC=33D 9' 34.24" +/- 0.2", U-B = -0.73+/-0.18 PLATE-ID=00DV B-V = -0.01+/-0.13 E(B-V) = 0 SURF(5007)=1.5+/-0.19e-15 SURF(3727)=0.29+/-0.06e-15 W-LINE(5007)=32.6+/-4.5 W-LINE(3727)=25.8+/-4.5 Comments: COORDINATES ARE FROM GSC. 8299( 5) - 01/18/00 11:49 - [ 5] Visit: 01 Visit Priority: Visit Requirements: ORIENT 40D TO 50D 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 3C48 STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 5.0 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 2 3C48 STIS/C ACQ/PEA 52X0.2 MIRROR 1 5.0 S CD K ------------------------------------------------------------------------------------------------------------------------------------ 3 3C48 STIS/C ACCUM 52X0.2 G750M 6768 CR-SPLIT=4 1 4400 S CD ------------------------------------------------------------------------------------------------------------------------------------ 4 CCDFLAT STIS/C ACCUM 52X0.2 G750M 8825 2 DEF CD ------------------------------------------------------------------------------------------------------------------------------------ 5 3C48 STIS/C ACCUM 52X0.2 G750M 8825 CR-SPLIT=4 1 4400 S CD ------------------------------------------------------------------------------------------------------------------------------------ 6 CCDFLAT STIS/C ACCUM 52X0.2 G750M 8825 2 DEF CD ------------------------------------------------------------------------------------------------------------------------------------ 8299( 5) - 01/18/00 11:49 - [ 6] Visit: 02 Visit Priority: Visit Requirements: SAME ORIENT AS 1 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 3C48 STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 5.0 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 2 3C48 STIS/C ACQ/PEA 52X0.2 MIRROR 1 5.0 S CD K ------------------------------------------------------------------------------------------------------------------------------------ 3 3C48 STIS/C ACCUM 52X0.2 G750M 6768 CR-SPLIT=4,PATTERN=PERP-TO-SLIT, 1 4400 S POS TARG -0.3, 0 CD NUM-POS=2,STEP-SIZE=0.6, PATTERN-DIRECTION=PLUS ------------------------------------------------------------------------------------------------------------------------------------ 8299( 5) - 01/18/00 11:49 - [ 7] Visit: 03 Visit Priority: Visit Requirements: SAME ORIENT AS 1 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 3C48 STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 5.0 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 2 3C48 STIS/C ACQ/PEA 52X0.2 MIRROR 1 5.0 S CD K ------------------------------------------------------------------------------------------------------------------------------------ 3 3C48 STIS/C ACCUM 52X0.2 G750M 6768 CR-SPLIT=4,PATTERN=PERP-TO-SLIT, 1 4400 S POS TARG 0.6, 0 CD NUM-POS=2,STEP-SIZE=0.3, PATTERN-DIRECTION=PLUS ------------------------------------------------------------------------------------------------------------------------------------ 8299( 5) - 01/18/00 11:49 - [ 8] Summary Form for Proposal 8299 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures F28X50LP 52X0.2 ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ ACQ/PEAK ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ACQTYPE=POINT CR-SPLIT=4 PATTERN-DIRECTION=PLUS STEP-SIZE=0.3 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENT 40D TO 50D SAME ORIENT AS 1 POS TARG -0.3, 0 POS TARG 0.6, 0 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR G750M ------------------------------------------------------------------------------------------------------------------------------------ Target Names 3C48 CCDFLAT ------------------------------------------------------------------------------------------------------------------------------------ Wavelengths 6768 8825 ------------------------------------------------------------------------------------------------------------------------------------