14152( 2) - 07-Jul-2015 15:19:54 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 14152 Version: 2 Check-in Time: 07-Jul-2015 15:19:54 STScI Edit Number: 0 Title Hot gas cooling and turbulence in the 3C326N radio-galaxy ------------------------------------------------------------------------------------ Type Cycle GO 23 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Pierre Guillard CNRS, Institut d'Astrophysique de Paris Y CoI: Dr. Matthew D. Lehnert CNRS, Institut d'Astrophysique de Paris N CoI: Dr. Francois B. Boulanger Institut d'Astrophysique Spatiale N CoI: Dr. Edith Falgarone Ecole Normale Superieure N CoI: Dr. Volker Gaibler Zentrum fur Astronomie - Universitat N Heidelberg CoI: Dr. Marc-Antoine Institut d'Astrophysique Spatiale N Miville-Deschenes CoI: Prof. Guillaume Pineau des Forets Institut d'Astrophysique Spatiale N ------------------------------------------------------------------------------------ Abstract The 3C326N radio-galaxy is one of the best examples of negative AGN feedback: with 2e9 Msun of molecular gas, its star formation rate is below 0.07 Msun/year, 20 times lower than what the Kennicutt law predicts. Why there is so much of molecular gas and why it is not forming stars? Powerful mid-IR H2 emission and very broad optical and far-IR lines suggest that strong turbulence may heat the H2 gas and prevent it from being gravitationnally bound at all scales. The turbulence driven at large scales by the radio jet would cascade down to smaller scales where it is dissipated. It must be powerful enough to drive high-speed shocks (100-400 km/s) in the hot (1e7 K) plasma that will compress it and allows it to cool down to temperatures where the gas becomes molecular. This cooling is expected to occur through UV line emission, and especially through CIV and OVI lines. To test this prediction, we propose to observe those lines in the 3C326N radio-galaxy. This will allow us to: (1) determine whether UV line emission is a significant cooling process of the hot gas, compute the mass cooling rate of the hot gas (is it high enough to form the H2 disk?), and (2) test our model of the multiphase turbulent gas energized by a radio-jet which would account for both H2 masses and energetics (can turbulence be sustained by shocks pressurizing the disk?). These observations will greatly enhance our understanding of why 3C~326N, and massive early-type galaxies in general, have large masses of molecular gas but yet weak star formation. The physics explored in this proposal applies to a wide range of environments, including cluster cooling flows and hot gas cooling in haloes of galaxies. ------------------------------------------------------------------------------------ Observations Description ------------------------ We request observations of the 3C326N radio-galaxy at moderate resolution using the G130M and G160M settings for all positions. This ensures, even if the emission is extended, a minimum resolution of 1400, which is enough to avoid line blending issues that we may encounter with the low-resolution grating. In order to achieve continuous spectral coverage and minimize fixed pattern noise, observations in each grating will be made at two (three) central wavelengths 14152( 2) - 07-Jul-2015 15:19:54 - [ 2] for G140L (G130M and G160M). The O{\sc vi} and C{\sc iv} lines are redshifted at 1138A and 1703A, so we will use central wavelengths settings at 1222 and 1096A for G130M and 1589 and 1600A for G160M. Note that the Lya line falls in the 1222A G130M setting. We will optimize S/N using the on-orbit line spread function and correcting for fixed pattern noise. We will also dither instrumental and gain-sag features. ------------------------------------------------------------------------------------ 14152( 2) - 07-Jul-2015 15:19:54 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 3C-326 GALAXY, RADIO GALAXY RA=15H52M9.1200S +/- 0.2", J2000 Z = V = 13.5 +/- 1.0 DEC=+20D05'48.50" +/- 0.2" 0.09002 Reference Frame: ICRS Extended: YES Comments: This object was generated by the targetselector and retrieved from the NED database. ------------------------------------------------------------------------------------------------------------------------------------ 14152( 2) - 07-Jul-2015 15:19:54 - [ 4] Visit: 01 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 3C-326 COS/NUV ACQ/IMA PSA MIRRORA 1 60 S (60 GE S) ------------------------------------------------------------------------------------------------------------------------------------ 2 3C-326 COS/FUV TIME-TA PSA G130M 1096 BUFFER-TIME=5160, FP-POS=ALL 1 1100 S G see below (5106 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 3C-326 COS/FUV TIME-TA PSA G130M 1222 BUFFER-TIME=7780, FP-POS=ALL 1 1100 S G see below (5075 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 3C-326 COS/FUV TIME-TA PSA G160M 1589 BUFFER-TIME=6520, FP-POS=ALL 1 300 S G see below (1284 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 3C-326 COS/FUV TIME-TA PSA G160M 1600 BUFFER-TIME=6630, FP-POS=ALL 1 300 S G see below (1276 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 | ------------------------------------------------------------------------------------------------------------------------------------ 3C-326 1 COS/NUV ACQ/IMA PSA MIRRORA none none none none 1 N/A GE 3C-326 2 COS/FUV TIME-TA PSA G130M 1096 none none none 1 1 1147.0 S G 3C-326 2 COS/FUV TIME-TA PSA G130M 1096 none none none 2 1 1147.0 S G 3C-326 2 COS/FUV TIME-TA PSA G130M 1096 none none none 3 2 1406.0 S G 3C-326 2 COS/FUV TIME-TA PSA G130M 1096 none none none 4 2 1406.0 S G 3C-326 3 COS/FUV TIME-TA PSA G130M 1222 none none none 1 3 1410.0 S G 3C-326 3 COS/FUV TIME-TA PSA G130M 1222 none none none 2 3 1411.0 S G 3C-326 3 COS/FUV TIME-TA PSA G130M 1222 none none none 3 4 1127.0 S G 14152( 2) - 07-Jul-2015 15:19:54 - [ 5] 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 | ------------------------------------------------------------------------------------------------------------------------------------ 3C-326 3 COS/FUV TIME-TA PSA G130M 1222 none none none 4 4 1127.0 S G 3C-326 4 COS/FUV TIME-TA PSA G160M 1589 none none none 1 4 327.0 S G 3C-326 4 COS/FUV TIME-TA PSA G160M 1589 none none none 2 5 319.0 S G 3C-326 4 COS/FUV TIME-TA PSA G160M 1589 none none none 3 5 319.0 S G 3C-326 4 COS/FUV TIME-TA PSA G160M 1589 none none none 4 5 319.0 S G 3C-326 5 COS/FUV TIME-TA PSA G160M 1600 none none none 1 5 319.0 S G 3C-326 5 COS/FUV TIME-TA PSA G160M 1600 none none none 2 5 319.0 S G 3C-326 5 COS/FUV TIME-TA PSA G160M 1600 none none none 3 5 319.0 S G 3C-326 5 COS/FUV TIME-TA PSA G160M 1600 none none none 4 5 319.0 S G 14152( 2) - 07-Jul-2015 15:19:54 - [ 6] Summary Form for Proposal 14152 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures PSA ------------------------------------------------------------------------------------------------------------------------------------ Configurations COS/FUV, COS/NUV ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ/IMAGE, TIME-TAG ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters BUFFER-TIME=5160, BUFFER-TIME=6520, BUFFER-TIME=6630, BUFFER-TIME=7780, FP-POS=ALL ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G130M, G160M, MIRRORA ------------------------------------------------------------------------------------------------------------------------------------ Target Names 3C-326 ------------------------------------------------------------------------------------------------------------------------------------