Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 2177c Report Date: 09-May-96:16:55 Version: ********** Check-in Date: ********** 1.Proposal Title: THE EXTENDED FEATURELESS CONTINUUM SOURCE IN CYGNUS A ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Proposal Type 5. Continuation ID QUASARS & AGN GO Sub Category RADIO GALAXIES ------------------------------------------------------------------------------------ 6. Principal Investigator Institution Country Telephone Robert Antonucci STSCI USA PROF. ------------------------------------------------------------------------------------ 7. Abstract Cygnus A is by far the nearest luminous Classical Double radio galaxy.The nuclear spectrum shows the canonical mix of light from old stars, a strong featureless continuum (FC), and a very strong, high ionization emission line spectrum. Several observers have recently come to the astonishing conclusion that the featureless continuum is spatially resolved.(There is no reason to think Cygnus A is unusual in this respect: if other luminous Classical Doubles had the same size optical source, their angular sizes would be too small to resolve from the ground).Furthermore, the obvious explanations of scattered light from a point source, and of optical synchrotron radiation, are strongly disfavored by optical polarization mapping. The only idea seriously considered in the literature for such an extended, unpolarized continuum is the Warmer theory, which unequivocally predicts Fv=v1 in the UV. We want to know whether the spectrum is Fv=v-1 as for quasars, or whether it rises rapidly with frequency as for Warmers. Also, if the 1550A continuum is dominated by normal O stars as in the starburst and some Warmer models we can diagnose it unequivocally via the CIV wind absorption. We cannot reliably determine the spectrum of the featureless continuum from the ground because of contamination by the light of old stars.We would also like to take a WFC picure in the UV, to understand the morphology of the featureless continuum source without confusion with the old stars. ------------------------------------------------------------------------------------ 8. Scientific Key Words: GALAXY; RADIO GALAXY ------------------------------------------------------------------------------------ 9. Est obs time (hours) pri: 4.66 par: 0 10. Num targs pri: 1 par: 0 ------------------------------------------------------------------------------------ 11. Instruments requested: FOS WF/PC ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 2177c PI: Robert Antonucci Proposal Title: THE EXTENDED FEATURELESS CONTINUUM SOURCE IN CYGNUS A ------------------------------------------------------------------------------------ 1. Proposers: Proposers Institution Country ESA ------------------------------------------------------------------------------------ Prof. Robert Antonucci UCSB USA A L Kinney STSCI USA ------------------------------------------------------------------------------------ 3. Description of proposed observations. First we will take a WFC image with the F336W filter. The Featureless Continuum flux at 5135A is 3.0x10-16 ergs/cm2 sec A (Osterbrock and Miller 1975),equivalent to 7.0x10-16 ergs/cm2 sec A at 3360A if Fv alpha nu0 (Warmer hypothesis with Galactic reddening allowance), and 3.0x10-16 ergs/cm2 sec A if Fv alpha nu-2. Imaging work described in the Sci. Just. shows that this will be spread over about 3 sq. arcsec. The WFC simulator (Ewald 1987) and ests. from the WF/PC Hand- book show that SNR=10/pix can be reached in 80 min under the conservative flux assumption. (Complimentary optical images are planned in the WF/PC IDT GTO program). In order to characterize the UV continuum, we request an exposure with the FOS Blue Tube, G160L grating, and also with the Red Tube and G270H grating. We will use the WFC picture to place the 4."3 aperture on the region brightest in the UV. We assume this includes half the UV flux, and make the con- servative nu -2 assumption. The FOS simulator indicates that that SNR=5 can be achieved with G160L in 76 min (with an approx. correction for the psf and aperture change). We can get SNR=6 in 76 minutes with G270H. We show our simulations below. (If the UV continuum is from hot stars, it will be much bluer so our SNR will be much higher, and the CIV absorption troughs easy to distinguish.) ------------------------------------------------------------------------------------ 11. Address Information Name: ROBERT ANTONUCCI Category: PI Institution: U. C., SANTA BARBARA Address: PHYSICS DEPARTMENT City: SANTA BARBARA State: CA Zip Code: 93106 Country: USA Telephone: Telex (or e-mail): ------------------------------------------------------------------------------------ TARGET LIST a) Fixed Targets ID = 2177c [ 3] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial |Acqui|FLX| Flux data No | Name | Description | Position |Eqnx | Vel. |Prblm|REF| | | | | | | | | ------------------------------------------------------------------------------------------------------------------------------------ 1 CYGNUS-A RADIO GALAXY RA=19H 57M 44.4S +/- 1", 1950 Z=.056 1 SURF(2300)=1.0 +/- 0.5E-16 DEC=40D 35' 46" +/- 1", Comments: V FLUX NOT GIVEN BECAUSE WE WILL NOT ACQUIRE DIRECTLY ON OUR TARGET. ------------------------------------------------------------------------------------------------------------------------------------ 2 CYGNUS-A- OFFSET STAR PLATE-ID=003S, 2000 BKG 1 V=15.0 +/- 0.5 OFFSET RA=19H 59M 24.972S +/- 1.0", DEC=40D 44' 23.78" +/- 1.0" ------------------------------------------------------------------------------------------------------------------------------------ 3 CYGNUS-A- NUCLEUS OF CYGNUS-A TBD-EARLY, 1950 1 F(2700)=3.0 +/- 2.0E-16 NUCLEUS RA=19H 57M 44.4S +/- 3.0", 2 F(1600)=5.0 +/- 4.0E-16 DEC=40D 35' 46" +/- 3.0", Comments: TBD-EARLY ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 2177c [ 4] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |10 | 11 | 12 |13 |14| 15 ------------------------------------------------------------------------------------------------------------------------------------ Line | Seq | Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | S/N |Flx|Pr| Special Number | Name | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| |Rel. Time|Ref| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 CYGNUS-A WFC IMAGE ALL F336W 3360 CR- 2 2600S 10 1 1 CYCLE 1 TOLERANCE=0.0 EARLY ACQ FOR 2-4 ------------------------------------------------------------------------------------------------------------------------------------ 2 CYGNUS-A- FOS/BL ACQ/ 4.3 MIRROR 1 40S 1 CYCLE 1 OFFSET BINARY ONBOARD ACQ FOR 3- 4 ------------------------------------------------------------------------------------------------------------------------------------ 3 CYGNUS-A- FOS/BL ACCUM 4.3 G160L 1600 1 5716S 5 2 1 CYCLE 1 NUCLEUS Comments: NUCLEUS POSITION TO BE DETERMINED FROM WFC IMAGE. ------------------------------------------------------------------------------------------------------------------------------------ 4 CYGNUS-A- FOS/RD ACCUM 4.3 G270H 2700 1 5716S 6 1 1 CYCLE 1 NUCLEUS Comments: NUCLEUS POSITION TO BE DETERMINED FROM WFC IMAGE. ------------------------------------------------------------------------------------------------------------------------------------ Summary Form for Proposal 2177c [ 5] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC FOS/BL FOS/RD ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ACQ/BINARY ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-TOLERANCE=0.0 ------------------------------------------------------------------------------------------------------------------------------------ Proposal for GO ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours 4.66 ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category QUASARS & AGN ------------------------------------------------------------------------------------------------------------------------------------ Scientific Sub-category RADIO GALAXIES ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements CYCLE 1; EARLY ACQ FOR 2-4 ONBOARD ACQ FOR 3-4 CYCLE 1 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F336W MIRROR G160L G270H ------------------------------------------------------------------------------------------------------------------------------------ Target Names CYGNUS-A CYGNUS-A-OFFSET CYGNUS-A-NUCLEUS ------------------------------------------------------------------------------------------------------------------------------------