13489( 4) - 30-Sep-2013 12:34:01 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 13489 Version: 4 Check-in Time: 30-Sep-2013 12:34:01 STScI Edit Number: 0 Title Accretion Physics in Nearby FR1 Galaxies ------------------------------------------------------------------------------------ Type Cycle GO 21 ------------------------------------------------------------------------------------ Investigators Contact? PI: Prof. John T. Stocke University of Colorado at Boulder Y CoI: Dr. Charles W. Danforth University of Colorado at Boulder Y CoI: Prof. Mitchell C. Begelman University of Colorado at Boulder N CoI: Prof. Eric S. Perlman Florida Institute of Technology N ------------------------------------------------------------------------------------ Abstract We propose to obtain COS G130M spectra of three of the nearest FR1 radio galaxies including M87 in order to measure Lyman alpha emission line and ionizing continuum luminosities to test accretion models. The accretion process in FR1s is poorly understood. The absence of a luminous accretion disk in these "radio mode'' AGN has led to various "radiatively inefficient accretion flow'' (RIAF) models, but whose basic parameters remain poorly quantified. While our serendipitous discovery of weak 10^40 ergs/s Lya emission in a few BLLac Objects strongly suggests that RIAFs must contain some cool material close to the black hole, our result was partly compromised by beaming; i.e., while the Lya emission line is unbeamed, the BLLac continuum is beamed. To overcome this shortcoming we propose to obtain COS FUV spectroscopy of representative FR1s to determine their Lya emission line luminosity, FWHM and line shape as well as their unbeamed ionizing continuum luminosity. These measurements will allow us to estimate the location, kinematics and amount of cool mass in the FR1 broad-line region. These observables will be used to test variants on the general RIAF scheme including models with "external accretion disks'' and out-flowing winds and models with magnetically regulated accretion flows. By using Lya emission we can probe regions very close to the nucleus, a factor of at least ten closer than the regions probed by diffuse X-ray emission. This will allow us to assess whether the very efficient accretion suggested by the X-ray analysis is plausible or whether a more sophisticated accretion model must be developed to understand these AGN and their powerful jets. ------------------------------------------------------------------------------------ Observations Description ------------------------ Each of our three FR 1 targets will be observed for two orbits using the COS G130M grating. While M 87 would require one orbit only to reach comparable absolute detection limits, this observation will provide the best data in our sample with which to characterize the Lyalpha emission line luminosity and width, to extrapolate to the ionizing continuum (with the help of an archival G160M spectrum) and to search for highly-ionized absorption lines (unlikely given their extreme orientation bias). For all but Hydra A, these exposure times are sufficient to detect Lya emission with a line luminosity of 1040 ergs s-1 and a FWHM = 1000 km s-1 (narrower emission will be easier to detect). Our exposure time for HydraA is based on making a high-S/N detection of both Lya and the UV continuum based on a previous IUE SWP spectrum. M 87 and Hydra A 13489( 4) - 30-Sep-2013 12:34:01 - [ 2] already have Lya and weak continuum detections from previous HST/FOS (Sankrit, Sembach & Canizares 1999; Figure 3) and IUE FUV spectra respectively. NGC 4696 has only a snapshot FUSE spectrum in the FUV but the large aperture of FUSE allowed the detection of only starlight through the large (30x30") aperture. Centering the COS aperture on the nucleus of these nearby galaxies will provide best COS resolution on the nucleus and a deweighting of the intensity and spectral resolution of starlight or shock emission from the inner bulges of these galaxies because it will be mostly off-axis or outside the aperture entirely. In two of the nearest cases (M87 and NGC 4696) emission line filaments have been detected in the vicinity of the nucleus (e.g., Farage et al. 2010) but will be both depressed in intensity and offset in location even if within the COS prime observing aperture (mostly these filaments are well outside the COS 2.5" aperture). However, we will not be able to exclude the possibility that some of the Lya nuclear luminosity we detect is due to other excitation mechanisms (e.g., shocks; Dopita et al. 1997) in these nuclei. This makes the detected line luminosity a firm upper limit on the Lya produced by the nuclear non-thermal emission, but given the luminosity of the shock emission seen elsewhere in these galaxies the nuclear photo-ionized emission will be dominant. The non-thermal continuum of these sources is likely to be quite weak. M87 has an observed FUV flux (FOS; Sankrit et al. 1999) of ~1 x 10-15 ergs s-1 cm-2A-1, which will be barely detected at native COS resolution. However, for all three sources we will smooth our spectra in bins up to 20A to detect the continuum and measure its power-law slope, a process which does not at all degrade the S/N gain because the COS FUV detectors are nearly noiseless. We expect to be able to detect the continuum down to well below 6x10-16 ergs s-1 cm-2 A-1 in these spectra after binning. These three targets were selected to span a range from little or no continuum detected (NGC 4696) to weak continuum (M 87) to moderately strong continuum (Hydra A). Regardless, we expect to detect weak Lya emission in all cases. M87's HST Knot #1 lies 0.85" from the nucleus of M87 and will be within the COS aperture. We request a specific range of spacecraft orientations to offset the spectrum of Knot #1 0.8" in the cross-dispersion direction. France et al. (2012) have demonstrated spatially resolved spectra of sources at this separation. We will certainly be able to distinguish any Lya emission from HST Knot #1 from the nuclear emission with minimal blending. The flux of this second source will most probably be fainter than the nucleus as it has been in all HST and Chandra observations since 2006. Even if 10 times brighter than in recent observations, its presence will not over-range the COS detectors using the G130M grating. Even a 10x brightening is a larger flare than the peak in March-May 2005 (Harris et al. 2006). Furthermore, the off-center position of HST Knot #1 will reduce the its flux by 33% due to vingetting in the COS aperture. Real Time Justification ----------------------- Calibration Justification 13489( 4) - 30-Sep-2013 12:34:01 - [ 3] ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 13489( 4) - 30-Sep-2013 12:34:01 - [ 4] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 M87-NUCLEUS GALAXY, BLR, NLR, RA=12H30M49.4234S +/- .0006", J2000 V = 8.63 f(FUVcontinuum)<1e-15 erg cm-2 NUCLEUS, RADIO GALAXY DEC=+12D23'27.04" +/- .0006" s-1 A-1 Reference Frame: ICRS Comments: This object was generated by the targetselector and retrieved from the SIMBAD database. Coords from VLBI centroid. ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC4696-NUCL GALAXY, BLR, NLR, RA=12H48M49.2569S +/- .07", J2000 V = 12.8 +/- 1 EUS NUCLEUS DEC=-41D18'39.34" +/- .07" Reference Frame: ICRS Comments: This object was generated by the targetselector and retrieved from the SIMBAD database. Coordinates checked in GSC2.3 (hstID=2MIOY63L) ------------------------------------------------------------------------------------------------------------------------------------ 3 HYDRA-A-NUCL GALAXY, BLR, NLR, RA=09H18M5.6740S +/- .01", J2000 V = 14.8 EUS NUCLEUS, RADIO GALAXY DEC=-12D05'43.92" +/- .01" Reference Frame: ICRS Comments: This object was generated by the targetselector and retrieved from the SIMBAD database. Coordinates courtesy of Greg Taylor from VLBI measurements. ------------------------------------------------------------------------------------------------------------------------------------ 13489( 4) - 30-Sep-2013 12:34:01 - [ 5] Visit: 01 Visit Requirements: ORIENT 46D TO 84 D; ORIENT 226D TO 264 D On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 M87-NUCLEUS COS/FUV ACQ/PEA PSA G130M 1318 1 30 S (30 KXD S) Comments: Penton's suggested strategy 9/27/13 ------------------------------------------------------------------------------------------------------------------------------------ 2 M87-NUCLEUS COS/FUV ACQ/PEA PSA G130M 1318 NUM-POS=5, STEP-SIZE=1 1 10 S (10 KD S) ------------------------------------------------------------------------------------------------------------------------------------ 3 M87-NUCLEUS COS/FUV TIME-TA PSA G130M 1318 BUFFER-TIME=600, FP-POS=1 1 1000 S G (1000 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 M87-NUCLEUS COS/FUV TIME-TA PSA G130M 1309 BUFFER-TIME=600, FP-POS=2 1 1000 S G (1000 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 M87-NUCLEUS COS/FUV TIME-TA PSA G130M 1300 BUFFER-TIME=600, FP-POS=3 1 1200 S G (1200 S) ------------------------------------------------------------------------------------------------------------------------------------ 6 M87-NUCLEUS COS/FUV TIME-TA PSA G130M 1291 BUFFER-TIME=600, FP-POS=4 1 1200 S G (1200 S) ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ M87-NUCLEUS 1 COS/FUV ACQ/PEA PSA G130M 1318 none none none none 1 N/A KXD M87-NUCLEUS 2 COS/FUV ACQ/PEA PSA G130M 1318 none none none none 1 N/A KD M87-NUCLEUS 3 COS/FUV TIME-TA PSA G130M 1318 none none none none 1 N/A G M87-NUCLEUS 4 COS/FUV TIME-TA PSA G130M 1309 none none none none 1 N/A G M87-NUCLEUS 5 COS/FUV TIME-TA PSA G130M 1300 none none none none 2 N/A G M87-NUCLEUS 6 COS/FUV TIME-TA PSA G130M 1291 none none none none 2 N/A G 13489( 4) - 30-Sep-2013 12:34:01 - [ 6] Visit: 02 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC4696-NUC COS/NUV ACQ/IMA PSA MIRRORA 1 15 S (15 LEUS GE S) Comments: HST program 12260 acquired M87 nucleus with a 12 second exposure. We duplicate that exposure here but use a more conservative continuum flux estimate. ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC4696-NUC COS/FUV TIME-TA PSA G130M 1291 BUFFER-TIME=600, FP-POS=1 1 900 S LEUS G see below (1191 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC4696-NUC COS/FUV TIME-TA PSA G130M 1300 BUFFER-TIME=600, FP-POS=2 1 900 S LEUS G see below (1191 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC4696-NUC COS/FUV TIME-TA PSA G130M 1318 BUFFER-TIME=600, FP-POS=3 1 900 S LEUS G see below (1417 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 NGC4696-NUC COS/FUV TIME-TA PSA G130M 1327 BUFFER-TIME=600, FP-POS=3 1 900 S LEUS G see below (1417 S) ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ NGC4696-NUCLEUS 1 COS/NUV ACQ/IMA PSA MIRRORA none none none none 1 N/A GE NGC4696-NUCLEUS 2 COS/FUV TIME-TA PSA G130M 1291 none none none none 1 1191.0 S G NGC4696-NUCLEUS 3 COS/FUV TIME-TA PSA G130M 1300 none none none none 1 1191.0 S G NGC4696-NUCLEUS 4 COS/FUV TIME-TA PSA G130M 1318 none none none none 2 1417.0 S G NGC4696-NUCLEUS 5 COS/FUV TIME-TA PSA G130M 1327 none none none none 2 1417.0 S G 13489( 4) - 30-Sep-2013 12:34:01 - [ 7] Visit: 03 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 HYDRA-A-NUC COS/NUV ACQ/SEA PSA MIRRORA SCAN-SIZE=2, CENTER=BRIGHTEST 1 15 S (15 LEUS RCH S) Comments: HST program 12260 acquired M87 nucleus with a 12 second exposure. We duplicate that exposure here but use a more conservative continuum flux estimate. ------------------------------------------------------------------------------------------------------------------------------------ 2 HYDRA-A-NUC COS/NUV ACQ/IMA PSA MIRRORA 1 60 S (60 LEUS GE S) ------------------------------------------------------------------------------------------------------------------------------------ 3 HYDRA-A-NUC COS/FUV TIME-TA PSA G130M 1291 BUFFER-TIME=600, FP-POS=1 1 900 S LEUS G see below (990 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 HYDRA-A-NUC COS/FUV TIME-TA PSA G130M 1309 BUFFER-TIME=600, FP-POS=2 1 900 S LEUS G see below (990 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 HYDRA-A-NUC COS/FUV TIME-TA PSA G130M 1318 BUFFER-TIME=600, FP-POS=3 1 900 S LEUS G see below (1380 S) ------------------------------------------------------------------------------------------------------------------------------------ 6 HYDRA-A-NUC COS/FUV TIME-TA PSA G130M 1327 BUFFER-TIME=600, FP-POS=3 1 900 S LEUS G see below (1380 S) ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ HYDRA-A-NUCLEUS 1 COS/NUV ACQ/SEA PSA MIRRORA none none none none 1 N/A RCH HYDRA-A-NUCLEUS 2 COS/NUV ACQ/IMA PSA MIRRORA none none none none 1 N/A GE HYDRA-A-NUCLEUS 3 COS/FUV TIME-TA PSA G130M 1291 none none none none 1 990.0 S G HYDRA-A-NUCLEUS 4 COS/FUV TIME-TA PSA G130M 1309 none none none none 1 990.0 S G HYDRA-A-NUCLEUS 5 COS/FUV TIME-TA PSA G130M 1318 none none none none 2 1380.0 S G 13489( 4) - 30-Sep-2013 12:34:01 - [ 8] Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ HYDRA-A-NUCLEUS 6 COS/FUV TIME-TA PSA G130M 1327 none none none none 2 1380.0 S G 13489( 4) - 30-Sep-2013 12:34:01 - [ 9] Summary Form for Proposal 13489 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures PSA ------------------------------------------------------------------------------------------------------------------------------------ Configurations COS/FUV, COS/NUV ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ/IMAGE, ACQ/PEAKD, ACQ/PEAKXD, ACQ/SEARCH, TIME-TAG ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters BUFFER-TIME=600, CENTER=BRIGHTEST, FP-POS=1, FP-POS=2, FP-POS=3, FP-POS=4, NUM-POS=5, SCAN-SIZE=2, STEP-SIZE=1 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENT 226D TO 264 D, ORIENT 46D TO 84 D ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G130M, MIRRORA ------------------------------------------------------------------------------------------------------------------------------------ Target Names HYDRA-A-NUCLEUS, M87-NUCLEUS, NGC4696-NUCLEUS ------------------------------------------------------------------------------------------------------------------------------------