The Star Formation Rate In Nearby Elliptical Galaxies

The Star Formation Rate In Nearby Elliptical Galaxies Small amounts of star formation in normal elliptical galaxies are suggested by several results: some surprisingly young ages from optical line-index dating; cooling X-ray gas; and mid-IR dust emission. Previously, it was difficult to detect low levels of star formation, but UV imaging with WFPC3 will permit us to conclusively identify individual O/B stars in nearby normal ellipticals by their UV colors and magnitudes. This technique is orders of magnitude more sensitive than previous methods, allowing detections of star formation to levels of 1E-4 Msolar/yr. Proof of concept is provided by a very long UV ACS observation of M87 that revealed many O/B stars. We propose observations of four normal ellipticals where recent star formation is likely. This will yield their star formation rates and the locations of such activity.

For each galaxy, we will observe two orbits in F225W (4 dithered exposures per orbit) followed by one orbit in F336W (4 dithered exposures). To check for nova, we will observe after a minimum of 30 days one additional orbit in F336W (4 dithered exposures). To maximize ease of scheduling we will not constrain the roll angle for any observation except that the first 3 orbits on each galaxy must be done at the same pointing. All observations will be in WFPC3/UVIS. UNRESOLVED STELLAR POPULATIONS AND GALAXY STRUCTURE 12 false 0.0 0.0 false false false false false SUPPORTED GALAXY ELLIPTICAL This object was generated by the targetselector and retrieved from the NED database. J2000 12 48 35.9000 -05 48 3.00 J2000 GALAXY ELLIPTICAL This object was generated by the targetselector and retrieved from the NED database. J2000 12 42 49.9000 +02 41 16.00 J2000 GALAXY ELLIPTICAL This object was generated by the targetselector and retrieved from the NED database. J2000 12 25 3.7000 +12 53 13.00 J2000 GALAXY ELLIPTICAL This object was generated by the targetselector and retrieved from the NED database. J2000 10 47 49.6000 +12 34 54.00 J2000 WFC3/UVIS Imaging No No F225W WFC3/UVIS Imaging No No F275W WFC3/UVIS Imaging No No F225W WFC3/UVIS Imaging No No F275W WFC3/UVIS Imaging No No F225W WFC3/UVIS Imaging No No F275W WFC3/UVIS Imaging No No F225W WFC3/UVIS Imaging No No F275W POS-TARG DITHER 0.173 LINE 0.112 false false 81.785 4 23.884 WFC3-UVIS-DITHER-BOX 1

false

Timing link suitability includes constraints ([21 After 01 by 21.0 to 180.0 days]) The scheduling data was generated by CASM 17.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 11583 :visit-id "01" :proposal-version -1 :trans-version "20080624" :date "02-Jul-2008 13:20:39.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 3 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 3465008 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11583 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11583 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2838 :al-overhead-at-end 116 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3242 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11583 :visit-id "01" :orbit-number 2 :pcs-time 195 :si-vis-utilization 2838 :al-overhead-at-end 116 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3242 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11583 :visit-id "01" :orbit-number 3 :pcs-time 195 :si-vis-utilization 2838 :al-overhead-at-end 116 :internal-dur-at-end 670 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3242 :pcs-gap 0 ) true 3 0 Timing link suitability includes constraints ([21 After 01 by 21.0 to 180.0 days]) The scheduling data was generated by CASM 17.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 11583 :visit-id "21" :proposal-version -1 :trans-version "20080624" :date "02-Jul-2008 13:20:46.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 1154992 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11583 :visit-id "21" :obset-id "21" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11583 :visit-id "21" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2792 :al-overhead-at-end 116 :internal-dur-at-end 670 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3242 :pcs-gap 0 ) true 1 0 Timing link suitability includes constraints ([22 After 02 by 21.0 to 180.0 days]) The scheduling data was generated by CASM 17.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 11583 :visit-id "02" :proposal-version -1 :trans-version "20080624" :date "02-Jul-2008 13:20:56.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 3 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 3465008 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11583 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11583 :visit-id "02" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2838 :al-overhead-at-end 116 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3236 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11583 :visit-id "02" :orbit-number 2 :pcs-time 195 :si-vis-utilization 2838 :al-overhead-at-end 116 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3236 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11583 :visit-id "02" :orbit-number 3 :pcs-time 195 :si-vis-utilization 2838 :al-overhead-at-end 116 :internal-dur-at-end 670 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3236 :pcs-gap 0 ) true 3 0 Timing link suitability includes constraints ([22 After 02 by 21.0 to 180.0 days]) The scheduling data was generated by CASM 17.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 11583 :visit-id "22" :proposal-version -1 :trans-version "20080624" :date "02-Jul-2008 13:21:01.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 1154992 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11583 :visit-id "22" :obset-id "22" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11583 :visit-id "22" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2792 :al-overhead-at-end 116 :internal-dur-at-end 670 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3236 :pcs-gap 0 ) true 1 0 Timing link suitability includes constraints ([23 After 03 by 21.0 to 180.0 days]) The scheduling data was generated by CASM 17.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 11583 :visit-id "03" :proposal-version -1 :trans-version "20080624" :date "02-Jul-2008 13:21:07.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 3 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 3465008 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11583 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11583 :visit-id "03" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2838 :al-overhead-at-end 116 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3251 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11583 :visit-id "03" :orbit-number 2 :pcs-time 195 :si-vis-utilization 2838 :al-overhead-at-end 116 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3251 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11583 :visit-id "03" :orbit-number 3 :pcs-time 195 :si-vis-utilization 2838 :al-overhead-at-end 116 :internal-dur-at-end 670 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3251 :pcs-gap 0 ) false 3 0 Timing link suitability includes constraints ([23 After 03 by 21.0 to 180.0 days]) The scheduling data was generated by CASM 17.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 11583 :visit-id "23" :proposal-version -1 :trans-version "20080624" :date "02-Jul-2008 13:21:12.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 1154992 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11583 :visit-id "23" :obset-id "23" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11583 :visit-id "23" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2792 :al-overhead-at-end 116 :internal-dur-at-end 670 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3251 :pcs-gap 0 ) false 1 0 Timing link suitability includes constraints ([24 After 04 by 21.0 to 180.0 days]) The scheduling data was generated by CASM 17.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 11583 :visit-id "04" :proposal-version -1 :trans-version "20080624" :date "02-Jul-2008 13:21:18.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 3 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 3465008 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11583 :visit-id "04" :obset-id "04" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11583 :visit-id "04" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2838 :al-overhead-at-end 116 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3251 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11583 :visit-id "04" :orbit-number 2 :pcs-time 195 :si-vis-utilization 2838 :al-overhead-at-end 116 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3251 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11583 :visit-id "04" :orbit-number 3 :pcs-time 195 :si-vis-utilization 2838 :al-overhead-at-end 116 :internal-dur-at-end 670 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3251 :pcs-gap 0 ) true 3 0 Timing link suitability includes constraints ([24 After 04 by 21.0 to 180.0 days]) The scheduling data was generated by CASM 17.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 11583 :visit-id "24" :proposal-version -1 :trans-version "20080624" :date "02-Jul-2008 13:21:23.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 1154992 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11583 :visit-id "24" :obset-id "24" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11583 :visit-id "24" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2792 :al-overhead-at-end 116 :internal-dur-at-end 670 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3251 :pcs-gap 0 ) true 1 0