10088( 6) - 02/02/04 11:23 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 10088 Version: 6 Check-in Date: 02-Feb-2004 11:22:50 1.Proposal Title: A Chandra HETGS & HST view of the Warm and Lukewarm absorbers in IRAS13349+2438 ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 12 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Julia Lee Massachusetts Institute of Technology CoI: Claude Canizares Massachusetts Institute of Technology N CoI: Herman Marshall Massachusetts Institute of Technology N CoI: Gerard Kriss Space Telescope Science Institute Y CoI: Niel Brandt The Pennsylvania State University N CoI: Christopher Reynolds U. Maryland N CoI: Patrick Ogle UCSB N CoI: Shai Kaspi Tel-Aviv University N ------------------------------------------------------------------------------------ 5. Abstract We propose a 300~ks HETGS observation simultaneous with a 4--orbit HST (UV) observation to study the archetypal infrared quasar IRAS13349+2438. We will explore its enigmatic properties and search for signatures of embedded dust (implicated by the high extinction) in the warm absorber clouds of this object. We will plan to propose for simultaneous optical observations to be taken using the 6.5-m Magellan telescope (through the PI host institution). The X-ray spectra will give unprecedented high- resolution information for this source necessary for probing in detail the physical properties, chemical compositions and velocities of the material surrounding the AGN. We will additionally assess the `unresolved transition array' (UTA) reported for this object, and search for and measure the neutral Fe L edge seen in a similarly reddened AGN. This will be complemented with simultaneous HST UV spectra to determine the continuum shape and to assess whether the UV/X-ray absorbers in this system are related. The Chandra data will also allow us to look for narrow features at >2 keV. Such a broad waveband study of this object will enable us to obtain a complete picture of the geometry and physics of the system, as well as the physical processes which are responsible for the variability in the absorber. ------------------------------------------------------------------------------------ 10088( 6) - 02/02/04 11:23 - [ 2] Observations Description ------------------------ Archival HST spectra of IRAS13349+2438 obtained using the FOS show a reddened continuum with observed fluxes of $1.8 \times 10^{-15}~\rm erg~cm^{-2}~s^{- 1}~\AA^{-1}$ at 1700 \AA, and $2.3 \times 10^{-15}~\rm erg~cm^{-2}~s^{- 1}~\AA^{-1}$ at 3100 \AA, as well as broad {\sc C~iv} and Mg~{\sc ii}. We propose to obtain UV spectra of IRAS13349+2438 covering the 1150--3180 \AA\ band using the STIS low-resolution gratings G140L and G230L in a 4-orbit visit coordinated with Chandra. Given the strong variability previously seen in the X-ray, it is critical that the proposed UV observations be contemporaneous. UV absorption lines associated with X-ray warm absorbers often have EWs as low as 0.3 \AA\ (Crenshaw et al. 1999; Kriss et al. 2000). For a 3-$\sigma$ detection of 0.3 \AA\ at 1700 \AA, the wavelength of redshifted {\sc C~iv}, we require $\rm S/N \sim 3 \times 1.2 / 0.3 \AA = 12$, where 1.2 \AA\ is the resolution of the STIS G140L grating. To set a similar limit at 3100 \AA\ for the Mg~{\sc ii} line, where the resolution of grating G230L is 2.5 \AA, we require a S/N of 12 as well. IRAS13349+2438 has an orbital visibility of 55 m. Using the on-line STIS Exposure Time Calculator, a total integration time of 133 m (3-orbits, excluding overheads) with G140L through the 52X0.5 arcsec aperture will give a S/N of 13 at 1700 \AA. On the 4th orbit, we would observe with G230L/NUV-MAMA for 42 m. This will yield a S/N of 13 at 3100 \AA. Real Time Justification ----------------------- Our coordinated HST and Chandra observations were approved by the Chandra TAC at high priority. The 300 ks Chandra observation will require about 4 days to execute, so there is wide latitude in overlapping the HST and Chandra observations. Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 10088( 6) - 02/02/04 11:23 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 IRAS13349+24 GALAXY, SEYFERT RA=13H 37M 18.72S +/- 0.01S, J2000 Z=0.1076 V = 16.0 38 DEC=+24D 23' 02.9" +/- 0.2", 4 B-V = 1.5 PLATE-ID=01GF F-CONT(1700)=1.8+/-1.0e-15 Coordinate Source: GUIDE_STAR_CATALOG 10088( 6) - 02/02/04 11:23 - [ 4] Visit: 01 Visit Priority: Visit Requirements: SCHED 100% On Hold Comments: Additional Comments: To be coordinated with Chandra Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 IRAS13349+2 STIS/C ACQ F28X50L MIRROR 1 5.0 S 438 CD P ------------------------------------------------------------------------------------------------------------------------------------ 2 IRAS13349+2 STIS/F ACCUM 52X0.5 G140L 1425 1 2000 S EXPAND 438 UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 3 IRAS13349+2 STIS/F ACCUM 52X0.5 G140L 1425 1 2630 S EXPAND 438 UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 4 IRAS13349+2 STIS/F ACCUM 52X0.5 G140L 1425 1 2630 S EXPAND 438 UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 5 IRAS13349+2 STIS/N ACCUM 52X0.5 G230L 2376 1 2630 S EXPAND 438 UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 10088( 6) - 02/02/04 11:23 - [ 5] Summary Form for Proposal 10088 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures F28X50LP 52X0.5 ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD STIS/FUV-MAMA STIS/NUV-MAMA ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements SCHED 100% EXPAND ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR G140L G230L ------------------------------------------------------------------------------------------------------------------------------------ Target Names IRAS13349+2438 ------------------------------------------------------------------------------------------------------------------------------------ Wavelengths 1425 2376 ------------------------------------------------------------------------------------------------------------------------------------