11127( 2) - 05/09/07 11:26 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 11127 Version: 2 Check-in Time: 09-May-2007 15:26:07 STScI Edit Number: 0 Title Mapping the nebula surrounding the enigmatic X-ray source at the center of the Vela Jr SNR ------------------------------------------------------------------------------------ Type Cycle Parallel Pointing Tolerance GO 16 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Andrea De Luca CNR, Istituto di Astrofisica Spaziale CoI: Dr. Roberto Mignani Mullard Space Science Laboratory Y CoI: Dr. Patrizia A. Caraveo CNR, Istituto di Astrofisica Spaziale N CoI: Dr. Alberto Pellizzoni CNR, Istituto di Astrofisica Spaziale N CoI: Dr. Sandro Mereghetti CNR, Istituto di Astrofisica Spaziale N CoI: Prof. Giovanni F. Bignami Istituto Universitario di Studi Superiori N di Pavia ------------------------------------------------------------------------------------ Abstract A compact X-ray source, showing nothing but steady unpulsed thermal emission, lies close to the center of the young and nearby supernova remnant dubbed "Vela Jr". It is a typical member of a class of enigmatic sources, supposed to be the youngest members of the radio-quiet neutron star family. Quite surprisingly, we discovered in ground-based optical observations a small Halpha nebula spatially coincident with the X-ray source. Such a nebula potentially carries very important information on the nature of the X-ray source, which remains elusive in spite of large observational efforts. We propose to use the WFPC2 to collect high resolution Halpha images of the nebula in order to resolve its structure, to understand its nature, and to identify its connection with the X-ray source. Addressing all these points will also have important implications for our interpretation of the compact X-ray source and on of other objects of the same class. ------------------------------------------------------------------------------------ 11127( 2) - 05/09/07 11:26 - [ 2] Observations Description ------------------------ The observation is aimed at obtaining a precise high-resolution mapping in H- alpha ofthe nebula seen around the X-ray source at the center of the Vela Jr.SNR Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 11127( 2) - 05/09/07 11:26 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 CXOJ085201.4 ISM, EMISSION LINE RA=08H52M1.3800S +/- 0.1", DEC=- J2000 R=23.1 +/- 0.2 -461753 NEBULA, HOT GAS, SHOCK 46D17'53.34" +/- 0.1" FRONT Reference Frame: ICRS 11127( 2) - 05/09/07 11:26 - [ 4] Visit: 01 Visit Priority: 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| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 CXOJ085201. WFPC2 IMAGE PC1-FIX F656N CR-SPLIT=0.5 2 1000 S 4-461753 ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ CXOJ085201.4-46175 1 WFPC2 IMAGE PC1-FIX F656N none none 1 1 1 N/A 3 CXOJ085201.4-46175 1 WFPC2 IMAGE PC1-FIX F656N none none 1 2 1 N/A 3 CXOJ085201.4-46175 1 WFPC2 IMAGE PC1-FIX F656N none none 2 1 1 N/A 3 CXOJ085201.4-46175 1 WFPC2 IMAGE PC1-FIX F656N none none 2 2 1 N/A 3 11127( 2) - 05/09/07 11:26 - [ 5] Summary Form for Proposal 11127 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures PC1-FIX ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=0.5 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F656N ------------------------------------------------------------------------------------------------------------------------------------ Target Names CXOJ085201.4-461753 ------------------------------------------------------------------------------------------------------------------------------------