13730( 3) - 08-Oct-2014 20:00:02 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 13730 Version: 3 Check-in Time: 08-Oct-2014 20:00:02 STScI Edit Number: 1 Title Maps of Recent Star Formation to Match ALMA Observations of the Nearest Nuclear Starburst ------------------------------------------------------------------------------------ Type Cycle GO 22 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Adam Leroy The Ohio State University Y CoI: Dr. Erik Rosolowsky University of Alberta N CoI: Dr. Alberto Bolatto University of Maryland N CoI: Dr. Karin Sandstrom University of California - San Diego N CoI: Dr. Fabian Walter Max-Planck-Institut fur Astronomie, N Heidelberg ------------------------------------------------------------------------------------ Abstract We propose narrow band WFC3 infrared imaging of the central part of NGC 253, the nearest nuclear starburst, with the goal of imaging the location of recent star formation traced by the Paschen $\beta$ line. We will compare the distribution of Pa$\beta$ emission to our understanding of the molecular ISM, built on a series of successful ALMA programs. These have revealed the location of star-forming clouds, shells carved by feedback, molecular outflows emerging from the disk, and a rich suite of interstellar molecules. Knowing exactly where (and how many) stars are forming is key to make the best use of these data. From the comparison of ALMA and HST Pa$\beta$ data, we will be able to assess the efficiencies of feedback, test models of star formation, and help establish the interpretation of new molecular tracers. Our proposed observations target the off-line filter (F130N) and will be combined with archival on-line imaging (F128N). Right now, those on-line data are not useful for science because the broad band data are inadequate for a quality continuum subtraction. ------------------------------------------------------------------------------------ Observations Description ------------------------ This program aims to combine with the archive to produce relatively deep matched narrow band on and off line observations of Paschen Beta in the central part of the nearby starburst galaxy NGC 253. This will yield maps of ionizing photon production that are comparatively robust to extinction, which we aim to compare with existing and awarded ALMA observations of the dense, star-forming molecular gas (also at comparatively high resolution) in the same region. Variable, heavy extinction hampered the attempt in the archive to use broad band measurements for continuum subtraction so we pursue this simpler and more robust, though somewhat more costly approach. ------------------------------------------------------------------------------------ 13730( 3) - 08-Oct-2014 20:00:02 - [ 2] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC-253 GALAXY, STARBURST RA=00H47M33.1340S, J2000 V = 13.97 DEC=-25D17'17.52" Reference Frame: Other: SIMBAD Comments: This object was generated by the targetselector and retrieved from the SIMBAD database. ------------------------------------------------------------------------------------------------------------------------------------ 13730( 3) - 08-Oct-2014 20:00:02 - [ 3] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-IR-DITHER-LINE-3PT Pattern_Purpose DITHER Number_Of_Points 3 Point_Spacing 0.605 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 41.788 Angle_Between_Sides Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 13730( 3) - 08-Oct-2014 20:00:02 - [ 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 NGC-253 WFC3/IR MULTIAC IR-FIX F130N NSAMP=14, SAMP-SEQ=STEP100 1 DEF PATTERN 1 1 CUM (2397.699 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC-253 WFC3/IR MULTIAC IR-FIX F128N NSAMP=6, SAMP-SEQ=STEP100 1 DEF PATTERN 1 2 CUM (147.691 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 | ------------------------------------------------------------------------------------------------------------------------------------ NGC-253 1 WFC3/IR MULTIAC IR-FIX F130N 1 none none none 1 N/A CUM NGC-253 1 WFC3/IR MULTIAC IR-FIX F130N 2 none none none 1 N/A CUM NGC-253 1 WFC3/IR MULTIAC IR-FIX F130N 3 none none none 1 N/A CUM NGC-253 2 WFC3/IR MULTIAC IR-FIX F128N 1 none none none 1 N/A CUM NGC-253 2 WFC3/IR MULTIAC IR-FIX F128N 2 none none none 1 N/A CUM NGC-253 2 WFC3/IR MULTIAC IR-FIX F128N 3 none none none 1 N/A CUM 13730( 3) - 08-Oct-2014 20:00:02 - [ 5] Summary Form for Proposal 13730 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures IR-FIX ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/IR ------------------------------------------------------------------------------------------------------------------------------------ Opmodes MULTIACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters NSAMP=14, NSAMP=6, SAMP-SEQ=STEP100 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PATTERN 1 1, PATTERN 1 2 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F128N, F130N ------------------------------------------------------------------------------------------------------------------------------------ Target Names NGC-253 ------------------------------------------------------------------------------------------------------------------------------------