An HST Survey of the Mid-UV Morphology of Nearby Galaxies

2.3. Observations

All 37 selected galaxies were observed with WFPC2 during Cycle 9. Typically, we exposed 2 × 800-1000 s in F300W and 2 × 100-160 s in F814W. Exposures times were made flexible to optimally use the full HST orbit allocated per galaxy. Of the 24 galaxies located in the CVZ, 11 could indeed be scheduled there during Cycle 9. For these, exposure times were 3 × 400-500 s in both the F255W and F300W filters, and 2 × 100-160 s in F814W. In none of the 37 Cycle 9 targets did we see evidence for elevated sky-levels in F300W (see Section 2.1.4).

We adopted a linear dither pattern such that exposures in the same filter are offset by n + 0.34 WFC pixels in the case of two (non-CVZ), and n + 0.33 and n + 0.66 WFC pixels in the case of three exposures per filter (CVZ). Here, n is a multiple of 5 pixels (ideally 10-30 pixels in both directions to fill in the vignetted regions between the WFPC2 CCD's), and the pixel fractions assure optimal drizzling in a later stage. The actual shifts may slightly deviate from the listed values depending on the quality of the FGS lock achieved for a particular galaxy.

2.3.2. Ground-based Observations

Most of the ground-based UBVRI CCD images for the 37 galaxies in the present sample were obtained with the 1.8 m Vatican Advanced Technology Telescope (VATT) on Mt. Graham, with additional images taken with the 0.9 m telescope at Cerro Tololo (CTIO), the Danish 1.5 m telescope at the European Southern Observatory (ESO), the 2.1 m telescope at Kitt Peak (KPNO), the 2.2 m University of Hawaii telescope at Mauna Kea (UH), or the 1.0 m Jacobus Kapteyn Telescope (JKT) at La Palma. The optical data were obtained mostly with 2k × 2k CCD's. Further details are given in Matthews & Gallagher (1997), Eskridge et al. (2002b), and Taylor et al. (2002, in prep.).

Ground-based near-IR imaging was done using the 1.5 m telescope at Cerro Tololo, the ESO 2.2 m telescope, the Carnegie 2.5 m du Pont telescope at Las Campanas (LCO), or the 3.8 m United Kingdom InfraRed Telescope (UKIRT) at Mauna Kea, mostly with 256² HgCdTe-arrays (and 1024² in the case of the du Pont telescope). Images were obtained in JHK, or a subset of these filters. For further details on these near-IR data we refer to de Grijs et al. (1997), de Jong & van der Kruit (1994), and Eskridge et al. (2002b).

The JHK filters sample the underlying cooler (and usually older) stellar population, which in general also dominates the R and I-bands, so that the RIJHK filters in general reveal similar galaxy morphology. Morphological contrast is added through the younger stellar populations in the bluer and UV filters. Since the older stellar population dominates the RIJHK fluxes of earlier type galaxies, a comparison of these filters can in principle provide a measure of the dust content, whose effects are strongly wavelength dependent - noting the usual caveat that effects from dust and metallicity are hard to separate, and require spatially resolved spectroscopy in addition to broad-band photometry to address this quantitatively.

We aimed for a photometric zero-point accuracy better than 0.03-0.05 mag, in the optical as well as the near-IR. The ground-based CCD images were reduced following standard procedures, as described in Matthews & Gallagher (1997), and Neuschaefer & Windhorst (1995).

In Table 2 we summarize our Cycle 9 HST observations together with the UIT and ground-based images available to date. For WFPC2 observations, we list the HST roll-angle (PA_V3) and the nominal FWHM of the HST PSF; for ground-based observation, we list the airmass and the median FWHM in each image stack. These FWHM values were measured from unsaturated stellar images using SExtractor (Bertin & Arnouts, 1996). We clipped the FWHM distribution at 0".3 to filter out cosmic rays and bad pixels, and at 5 to filter out misclassified extended objects (e.g., H II or star-forming regions inside the galaxies of interest). These values, and the FWHM values of Moffat (1969) profiles as fitted using the task imexamine within IRAF, are consistent to within 2.5% with a dispersion of 9%. FWHM values could be measured for 124 (out of 131) ground-based images. For the remaining images that did not contain any unsaturated stars, the FWHM was estimated from the images taken closest in time that did. The mean (median) seeing over all ground-based images is 2".04 ± 0".52 (2".00 ± 0".52) (1- sigma ). This rather large average image-FWHM is due to the majority of VATT images having a focus component in their PSF as a result of the rapid change of focus with temperature in this f/1 telescope (for details, see Taylor et al. 2002). Even with FWHM ~ 20, these ground-based images are quite suitable for our current purpose of galaxy surface photometry in UBVR.

**Table 2.** Summary of *HST*, *UIT* and ground-based images of our Cycle 9 sample

Object	Telescop	Filter	Exposure time	Airmass	Orient	Zeropoint	Plate scale	FWHM	Fig.nr.
			(sec)		(deg)	(mag)	("/pix)	(")
(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)

NGC 1140 (Mrk 1063)	HST	F300W	2× 900.0	0	71.933	19.433	0.0996	0.04	3/4.28
	HST	F814W	2× 100.0	0	71.933	21.659	0.0996	0.08	3/4.28
	VATT	U	1× 300.0	1.364	0.0	---	0.3746	2.15	4.28
	VATT	B	1× 180.0	1.360	0.0	---	0.3746	2.59	4.28
	VATT	V	1× 180.0	1.358	0.0	---	0.3746	2.49	4.28
	POSS-II	IIIaF	1×3000.0	---	0.0	---	1.00	3.86	4.28
ESO 418-G008	HST	F300W	2× 900.0	0	151.410	19.433	0.0996	0.04	3/4.25
	HST	F814W	2× 130.0	0	151.410	21.659	0.0996	0.08	3/4.25
	VATT	U	1× 300.0	2.184	0.0	---	0.3746	2.80	4.25
	VATT	B	1× 360.0	2.186	0.0	---	0.3746	2.76	4.25
	VATT	V	1× 240.0	2.191	0.0	---	0.3746	2.50	4.25
	VATT	R	1× 120.0	2.197	0.0	---	0.3746	2.53	4.25
NGC 1396	UIT	150nm	1×1454.5	0	83.832	16.928	1.200	3.03	4.02
	UIT	250nm	1×1099.5	0	83.831	18.658	1.200	2.71	4.02
	HST	F300W	2× 900.0	0	22.975	19.433	0.0996	0.04	3/4.02
	HST	F814W	2× 130.0	0	22.975	21.659	0.0996	0.08	3/4.02
	POSS-I	IIIaJ	1×3600.0	---	0.0	---	1.70	5.0	4.02
	POSS-II	IIIaF	1×3600.0	---	0.0	---	1.00	3.56	4.02
NGC 1510	UIT	150nm	1× 948.5	0	0.020	16.806	1.137	3.03	4.26
	HST	F300W	2× 900.0	0	13.650	19.433	0.0996	0.04	3/4.26
	HST	F814W	2× 160.0	0	13.650	21.659	0.0996	0.08	3/4.26
	POSS-I	IIIaJ	1×4200.0	---	0.0	---	1.70	4.8	4.26
	POSS-II	IIIaF	1×3900.0	---	0.0	---	1.00	3.52	4.26
ESO 033-G022	HST	F300W	2×1000.0	0	254.257	19.433	0.0996	0.04	3/4.19
	HST	F814W	2× 130.0	0	254.257	21.659	0.0996	0.08	3/4.19
	ESO 1.5m	B	2×1500.0	---	0.28	22.331	0.36	1.7	4.19
	ESO 1.5m	V	1×2100.0	---	0.28	23.058	0.36	1.6	4.19
	ESO 1.5m	I	2× 900.0	---	0.28	22.351	0.36	0.9	4.19
UGC 03426 (Mrk 3)	UIT	150nm	2×1261.0	0	327.300	16.806	1.137	3.03	4.05
	HST	F255W	3× 466.7	0	119.723	17.037	0.0996	0.04	3/4.05
	HST	F300W	3× 500.0	0	119.723	19.433	0.0996	0.04	3/4.05
	HST	F814W	2× 130.0	0	119.723	21.659	0.0996	0.08	3/4.05
	VATT	U	1× 300.0	1.462	0.0	---	0.3746	1.96	4.05
	VATT	B	1× 180.0	1.502	0.0	---	0.3746	1.62	4.05
	VATT	V	1× 120.0	1.522	0.0	---	0.3746	1.52	4.05
	VATT	R	1× 30.0	1.553	0.0	---	0.3746	1.42	4.05
IC 2184 (Mrk 8)	HST	F255W	3× 466.7	0	139.416	17.037	0.0996	0.04	3/4.37
	HST	F300W	3× 500.0	0	139.416	19.433	0.0996	0.04	3/4.37
	HST	F814W	2× 130.0	0	139.416	21.659	0.0996	0.08	3/4.37
	VATT	U	1× 600.0	1.298	0.0	---	0.3746	2.12	4.37
	VATT	B	1× 300.0	1.298	0.0	---	0.3746	1.96	4.37
	VATT	V	1× 240.0	1.298	0.0	---	0.3746	2.00	4.37
	VATT	R	1× 180.0	1.302	0.0	---	0.3746	1.70	4.37
NGC 2551	UIT	150nm	1× 454.5	0	43.306	16.928	1.200	3.03	4.10
	UIT	250nm	1× 454.5	0	43.307	18.658	1.200	2.71	4.10
	HST	F300W	2×1000.0	0	232.495	19.433	0.0996	0.04	3/4.10
	HST	F814W	2× 130.0	0	232.495	21.659	0.0996	0.08	3/4.10
	VATT	U	1× 600.0	1.325	0.0	---	0.3746	1.60	4.10
	VATT	B	1× 180.0	1.325	0.0	---	0.3746	1.24	4.10
	VATT	V	1× 120.0	1.324	0.0	---	0.3746	1.15	4.10
	VATT	R	1× 120.0	1.324	0.0	---	0.3746	1.00	4.10
UGC 05028/29 (Arp 300)	HST	F300W	2× 950.0	0	350.000	19.433	0.0996	0.04	3/4.23
	HST	F814W	2× 160.0	0	350.000	21.659	0.0996	0.08	3/4.23
	POSS-II	IIIaJ	1×4800.0	---	0.0	---	1.00	3.48	4.23
	POSS-II	IIIaF	1×3000.0	---	0.0	---	1.00	3.40	4.23
UGC 05101	HST	F255W	3× 466.7	0	165.068	17.037	0.0996	0.04	3/4.08
	HST	F300W	3× 500.0	0	165.068	19.433	0.0996	0.04	3/4.08
	HST	F814W	2× 130.0	0	165.068	21.659	0.0996	0.08	3/4.08
	VATT	U	4× 300.0	1.223	0.0	25.000	0.3746	1.9	4.08
	VATT	B	1× 300.0	1.203	0.0	25.000	0.3746	2.0	4.08
	VATT	V	1× 240.0	1.197	0.0	25.000	0.3746	2.1	4.08
	VATT	R	1× 180.0	1.192	0.0	25.000	0.3746	2.1	4.08
	HST	F110W	1× 111.9	0	107.171	24.818	0.0758	0.11	4.08
	HST	F160W	1× 111.9	0	107.171	25.447	0.0758	0.16	4.08
	HST	F222M	1× 135.9	0	107.171	25.131	0.0758	0.22	4.08
UGC 05189	HST	F300W	2× 900.0	0	230.001	19.433	0.0996	0.04	3/4.33
	HST	F814W	2× 100.0	0	230.001	21.659	0.0996	0.08	3/4.33
	VATT	U	2×1200.0	1.1	0.0	25.000	0.3746	1.8	4.33
	VATT	B	2× 600.0	1.1	0.0	25.000	0.3746	1.6	4.33
	VATT	V	4× 480.0	1.1	0.0	25.000	0.3746	1.6	4.33
	VATT	R	2× 360.0	1.1	0.0	25.000	0.3746	1.5	4.33
UGC 05626	HST	F255W	3× 466.7	0	170.844	17.037	0.0996	0.04	3/4.29
	HST	F300W	3× 500.0	0	170.844	19.433	0.0996	0.04	3/4.29
	HST	F814W	2× 130.0	0	170.844	21.659	0.0996	0.08	3/4.29
	VATT	U	2×1200.0	1.417	0.0	25.000	0.3746	2.0	4.29
	VATT	B	2× 600.0	1.427	0.0	25.000	0.3746	1.9	4.29
	VATT	V	2× 480.0	1.436	0.0	25.000	0.3746	1.8	4.29
	VATT	R	2× 360.0	1.444	0.0	25.000	0.3746	1.8	4.29
NGC 3310 (Arp 217)	UIT	150nm	1×1130.5	0	112.049	16.806	1.1367	3.03	4.13
	HST	F300W	2× 950.0	0	165.015	19.433	0.0996	0.04	3/4.13
	HST	F814W	2× 130.0	0	165.015	21.659	0.0996	0.08	3/4.13
	VATT	U	1× 300.0	1.225	0.0	---	0.3746	2.10	4.13
	VATT	B	1× 150.0	1.232	0.0	---	0.3746	1.62	4.13
	VATT	V	1× 150.0	1.242	0.0	---	0.3746	2.21	4.13
	VATT	R	1× 150.0	1.251	0.0	---	0.3746	1.37	4.13
	HST	F160W	1× 256.0	0	80.830	21.100	0.2000	0.20	4.13
MCG+06-24-047	UIT	150nm	1×1430.5	0	127.736	16.806	1.1367	3.03	4.22
	HST	F300W	2× 900.0	0	145.410	19.433	0.0996	0.04	3/4.22
	HST	F814W	2× 130.0	0	145.410	21.659	0.0996	0.08	3/4.22
	VATT	U	2× 600.0	1.032	0.0	25.000	0.3746	2.5	4.22
	VATT	B	2× 300.0	1.030	0.0	25.000	0.3746	2.8	4.22
	VATT	V	2× 240.0	1.029	0.0	25.000	0.3746	2.5	4.22
	VATT	R	2× 180.0	1.186	0.0	25.000	0.3746	2.5	4.22
NGC 3516	UIT	150nm	1×1480.5	0	299.210	16.806	1.1367	3.03	4.04
	HST	F255W	3× 466.7	0	256.848	17.037	0.0996	0.04	3/4.04
	HST	F300W	3× 500.0	0	256.848	19.433	0.0996	0.04	3/4.04
	HST	F814W	2× 130.0	0	256.848	21.659	0.0996	0.08	3/4.04
	VATT	U	1× 300.0	1.636	0.0	---	0.3746	1.85	4.04
	VATT	B	1× 150.0	1.655	0.0	---	0.3746	1.80	4.04
	VATT	V	1× 100.0	1.662	0.0	---	0.3746	1.66	4.04
	VATT	R	1× 180.0	1.711	0.0	---	0.3746	2.00	4.04
NGC 3690/IC 0694	HST	F255W	3× 466.7	0	257.350	17.037	0.0996	0.04	3/4.34
(Arp 299, Mrk 171)	HST	F300W	3× 500.0	0	257.350	19.433	0.0996	0.04	3/4.34
	HST	F814W	2× 130.0	0	257.350	21.659	0.0996	0.08	3/4.34
	VATT	U	2× 600.0	1.120	0.0	---	0.3746	2.84	4.34
	UH 2.2m	B	1× 600.0	1.283	359.910	---	0.4400	1.4	4.34
	UH 2.2m	V	1× 900.0	1.284	359.910	---	0.4400	1.5	4.34
	UH 2.2m	R	1× 600.0	1.283	359.910	---	0.4400	1.5	4.34
	UH 2.2m	K	5× 120.0	1.286	0.006	---	0.2200	1.1	4.34
UGC 06527 (Arp 322,	HST	F300W	2× 950.0	0	251.824	19.433	0.0996	0.04	3/4.35
Mrk 176)	HST	F814W	2× 130.0	0	251.824	21.659	0.0996	0.08	3/4.35
	VATT	U	2×1200.0	1.083	0.0	25.000	0.3746	2.3	4.35
	VATT	B	2× 600.0	1.078	0.0	25.000	0.3746	2.6	4.35
	VATT	V	2× 480.0	1.077	0.0	25.000	0.3746	2.4	4.35
	VATT	R	2× 360.0	1.212	0.0	25.000	0.3746	2.5	4.35
	HST	F160W	1× 256.0	0	-6.017	21.100	0.2000	0.20	4.35
UGC 06697	UIT	150nm	1× 529.5	0	84.124	16.928	1.200	3.03	4.17
	UIT	250nm	1× 105.5	0	84.125	18.658	1.200	2.71	4.17
	HST	F300W	2× 900.0	0	286.763	19.433	0.0996	0.04	3/4.17
	HST	F814W	2× 100.0	0	286.763	21.659	0.0996	0.08	3/4.17
	VATT	U	2× 600.0	1.035	0.0	25.000	0.3746	2.3	4.17
	VATT	B	2× 300.0	1.032	0.0	25.000	0.3746	2.4	4.17
	VATT	V	3× 240.0	1.043	0.0	25.000	0.3746	2.2	4.17
	VATT	R	2× 180.0	1.162	0.0	25.000	0.3746	2.6	4.17
CGCG 097-094	UIT	150nm	1× 529.5	0	84.124	16.928	1.200	3.03	4.01
(observed in	UIT	250nm	1× 105.5	0	84.125	18.658	1.200	2.71	4.01
the field of	HST	F300W	2× 900.0	0	300.002	19.433	0.0996	0.04	3/4.01
MCG+03-30-071)	HST	F814W	2× 100.0	0	300.002	21.659	0.0996	0.08	3/4.01
	VATT	U	2× 600.0	1.045	0.0	25.000	0.3746	2.4	4.01
	VATT	B	2× 300.0	1.043	0.0	25.000	0.3746	2.4	4.01
	VATT	V	2× 240.0	1.042	0.0	25.000	0.3746	2.3	4.01
	VATT	R	2× 180.0	1.120	0.0	25.000	0.3746	2.2	4.01
MCG+03-30-071	UIT	150nm	1× 529.5	0	84.124	16.928	1.200	3.03	4.21
	UIT	250nm	1× 105.5	0	84.125	18.658	1.200	2.71	4.21
	HST	F300W	2× 900.0	0	300.002	19.433	0.0996	0.04	3/4.21
	HST	F814W	2× 100.0	0	300.002	21.659	0.0996	0.08	3/4.21
	VATT	U	2× 600.0	1.045	0.0	25.000	0.3746	2.4	4.21
	VATT	B	2× 300.0	1.043	0.0	25.000	0.3746	2.4	4.21
	VATT	V	2× 240.0	1.042	0.0	25.000	0.3746	2.3	4.21
	VATT	R	2× 180.0	1.120	0.0	25.000	0.3746	2.2	4.21
NGC 3860B	UIT	150nm	1× 529.5	0	84.124	16.928	1.200	3.03	4.24
	UIT	250nm	1× 105.5	0	84.125	18.658	1.200	2.71	4.24
	HST	F300W	2× 900.0	0	287.781	19.433	0.0996	0.04	3/4.24
	HST	F814W	2× 100.0	0	287.781	21.659	0.0996	0.08	3/4.24
	VATT	U	2× 600.0	1.036	0.0	25.000	0.3746	1.5	4.24
	VATT	B	2× 300.0	1.035	0.0	25.000	0.3746	1.6	4.24
	VATT	V	2× 240.0	1.034	0.0	25.000	0.3746	1.7	4.24
	VATT	R	2× 180.0	1.166	0.0	25.000	0.3746	2.4	4.24
NGC 3921 (Arp 224,	HST	F300W	2× 950.0	0	241.061	19.433	0.0996	0.04	3/4.07
Mrk 430)	HST	F814W	2× 130.0	0	241.061	21.659	0.0996	0.08	3/4.07
	UH 2.2m	B	2× 600.0	1.237	359.869	---	0.4400	?	4.07
	UH 2.2m	V	1× 900.0	1.250	359.869	---	0.4400	?	4.07
	UH 2.2m	R	1× 600.0	1.231	359.869	---	0.4400	?	4.07
	HST	F110W	1× 160.0	0	18.507	21.100	0.0758	0.11	4.07
	HST	F160W	1× 256.0	0	18.839	21.100	0.2000	0.20	4.07
	UH 2.2m	K'	3× 120.0	1.231	0.006	---	0.1850	?	4.07
NGC 4478	UIT	150nm	1× 352.5	0	303.985	16.928	1.200	3.03	4.03
	UIT	250nm	1× 70.5	0	303.985	18.658	1.200	2.71	4.03
	HST	F300W	2× 900.0	0	123.922	19.433	0.0996	0.04	3/4.03
	HST	F814W	2× 100.0	0	123.922	21.659	0.0996	0.08	3/4.03
	VATT	U	1× 300.0	1.072	0.0	---	0.3746	2.31	4.03
	VATT	B	1× 300.0	1.070	0.0	---	0.3746	2.10	4.03
	VATT	V	1× 200.0	1.066	0.0	---	0.3746	1.62	4.03
	VATT	R	1× 120.0	1.068	0.0	---	0.3746	1.70	4.03
IC 3949	UIT	150nm	1×1900.5	0	211.560	16.806	1.1367	3.03	4.18
	HST	F300W	2× 900.0	0	130.973	19.433	0.0996	0.04	3/4.18
	HST	F814W	2× 100.0	0	130.973	21.659	0.0996	0.08	3/4.18
	VATT	U	1× 300.0	1.392	0.0	---	0.3746	2.25	4.18
	VATT	B	1× 180.0	1.487	0.0	---	0.3746	1.77	4.18
	VATT	V	1× 120.0	1.539	0.0	---	0.3746	1.77	4.18
	VATT	R	1× 60.0	1.585	0.0	---	0.3746	1.21	4.18
UGC 08335 (Arp 238)	HST	F300W	2× 900.0	0	234.614	19.433	0.0996	0.04	3/4.36
	HST	F814W	2× 130.0	0	234.614	21.659	0.0996	0.08	3/4.36
	VATT	U	2× 600.3	1.399	0.0	---	0.3746	1.99	4.36
	POSS-II	IIIaJ	1×4500.0	---	0.0	---	1.00	3.15	4.36
	VATT	R	2× 180.1	1.388	0.0	---	0.3746	1.87	4.36
Mrk 66	UIT	150nm	1× 775.5	0	27.310	16.806	1.1367	3.03	4.32
	HST	F300W	2× 900.0	0	143.091	19.433	0.0996	0.04	3/4.32
	HST	F814W	2× 130.0	0	143.091	21.659	0.0996	0.08	3/4.32
	VATT	U	2× 600.1	1.143	0.0	---	0.3746	1.66	4.32
	VATT	B	2× 300.0	1.133	0.0	---	0.3746	1.75	4.32
	VATT	V	2× 240.8	1.128	0.0	---	0.3746	1.66	4.32
	VATT	R	2× 180.0	1.426	0.0	---	0.3746	2.27	4.32
NGC 5253	UIT	150nm	2× 726.1	0	163.350	16.806	1.1367	3.03	4.27
	HST	F255W	9× 766.7	0	264.709	17.037	0.0996	0.04	4.27
	HST	F300W	2× 900.0	0	291.500	19.433	0.0996	0.04	3/4.27
	HST	F814W	2× 130.0	0	291.500	21.659	0.0996	0.08	3/4.27
	VATT	U	5× 300.0	2.307	0.0	25.000	0.3746	3.3	4.27
	VATT	B	2× 300.0	2.304	0.0	25.000	0.3746	2.6	4.27
	VATT	V	2× 240.0	2.308	0.0	25.000	0.3746	2.5	4.27
	VATT	R	2× 180.0	2.314	0.0	25.000	0.3746	2.3	4.27
	LCO 2.5m	J	5× 50.0	0.500	0.0	22.20	0.3500	1.94	4.27
	LCO 2.5m	H	5× 30.0	0.500	0.0	21.96	0.3500	1.91	4.27
	LCO 2.5m	K	9× 20.0	0.500	0.0	21.62	0.3500	0.98	4.27
NGC 5278/79 (Arp 239,	HST	F255W	3× 466.7	0	126.600	17.037	0.0996	0.04	3/4.38
Mrk 271)	HST	F300W	3× 500.0	0	126.600	19.433	0.0996	0.04	3/4.38
	HST	F814W	2× 130.0	0	126.600	21.659	0.0996	0.08	3/4.38
	VATT	U	4× 300.7	1.496	0.0	---	0.3746	2.49	4.38
	POSS-II	IIIaJ	1×3900.0	---	0.0	---	1.00	3.4	4.38
	UH 2.2m	R	1× 600.0	1.352	359.684	---	0.4400	---	4.38
UGC 08696 (Mrk 273)	HST	F255W	3× 466.7	0	254.413	17.037	0.0996	0.04	3/4.09
	HST	F300W	3× 500.0	0	254.413	19.433	0.0996	0.04	3/4.09
	HST	F814W	2× 130.0	0	254.413	21.659	0.0996	0.08	3/4.09
	VATT	U	2× 303.8	1.645	0.0	---	0.3746	2.47	4.09
	UH 2.2m	R	1× 600.0	1.377	359.684	---	0.4400	---	4.09
	HST	F110W	4× 63.9	0	88.267	24.818	0.0758	0.11	4.09
	HST	F160W	4× 63.9	0	88.267	25.447	0.0758	0.16	4.09
	HST	F222M	4× 79.9	0	88.267	25.131	0.0758	0.22	4.09
UGC 08823 (Mrk 279)	UIT	150nm	2× 777.5	0	39.999	16.806	1.1367	3.03	4.06
	HST	F300W	2× 950.0	0	318.595	19.433	0.0996	0.04	3/4.06
	HST	F814W	2× 160.0	0	318.595	21.659	0.0996	0.08	3/4.06
	VATT	U	4× 300.0	1.333	0.0	25.000	0.3746	3.2	4.06
	VATT	B	2× 300.0	1.316	0.0	25.000	0.3746	3.1	4.06
	VATT	V	2× 240.0	1.317	0.0	25.000	0.3746	2.7	4.06
	VATT	R	2× 180.0	1.317	0.0	25.000	0.3746	2.6	4.06
IC 4393	HST	F300W	2× 900.0	0	150.001	19.433	0.0996	0.04	3/4.20
	HST	F814W	2× 130.0	0	150.001	21.659	0.0996	0.08	3/4.20
	VATT	U	2× 600.0	2.286	0.0	25.000	0.3746	2.4	4.20
	VATT	B	2× 300.0	2.291	0.0	25.000	0.3746	2.3	4.20
	VATT	V	2× 240.0	2.297	0.0	25.000	0.3746	2.2	4.20
	VATT	R	2× 180.0	2.304	0.0	25.000	0.3746	2.1	4.20
	ESO 1.5m	I	2×1200.0	---	1.46	20.928	0.36	1.2	4.20
	ESO 2.2m	K	24× 10.0	---	0.11	20.772	0.491	1.4	4.20
UGC 09855	HST	F255W	3× 466.7	0	291.667	17.037	0.0996	0.04<�/TD>	3/4.30
	HST	F300W	3× 500.0	0	291.667	19.433	0.0996	0.04	3/4.30
	HST	F814W	2× 130.0	0	291.667	21.659	0.0996	0.08	3/4.30
	VATT	U	2× 600.0	1.234	0.0	25.000	0.3746	2.7	4.30
	VATT	B	2× 240.0	1.255	0.0	25.000	0.3746	2.9	4.30
	VATT	V	2× 300.0	1.234	0.0	25.000	0.3746	2.5	4.30
	VATT	R	2× 180.0	1.264	0.0	25.000	0.3746	2.7	4.30
UGC 10043	HST	F300W	2× 900.0	0	250.001	19.433	0.0996	0.04	3/4.16
	HST	F814W	2× 100.0	0	250.001	21.659	0.0996	0.08	3/4.16
	VATT	U	2×1800.0	1.048	0.0	25.000	0.3746	1.5	4.16
	VATT	B	2×1200.0	1.158	0.0	25.000	0.3746	1.3	4.16
	VATT	V	2× 900.0	1.167	0.0	25.000	0.3746	1.1	4.16
	VATT	R	2× 600.0	1.331	0.0	25.000	0.3746	1.2	4.16
NGC 6753	HST	F300W	2× 950.0	0	154.222	19.433	0.0996	0.04	3/4.11
	HST	F814W	2× 160.0	0	154.222	21.659	0.0996	0.08	3/4.11
	CTIO 0.9m	U	1×1200.0	1.125	0.0	---	0.396	1.45	4.11
	CTIO 0.9m	B	4× 300.0	1.382	0.0	---	0.396	1.68	4.11
	CTIO 0.9m	V	3× 300.0	1.453	0.0	---	0.396	1.76	4.11
	CTIO 0.9m	R	3× 200.0	1.514	0.0	---	0.396	1.90	4.11
	CTIO 1.5m	J	...	---	0.0	---	0.645	1.11	4.11
	CTIO 1.5m	H	...	---	0.0	---	0.645	1.25	4.11
	CTIO 1.5m	K	...	---	0.0	---	0.645	1.10	4.11
NGC 6789	HST	F255W	3× 466.7	0	349.145	17.037	0.0996	0.04	3/4.31
	HST	F300W	3× 500.0	0	349.145	19.433	0.0996	0.04	3/4.31
	HST	F814W	2× 130.0	0	349.145	21.659	0.0996	0.08	3/4.31
	VATT	U	2× 600.0	1.674	0.0	25.000	0.3746	2.1	4.31
	VATT	B	2× 300.0	1.676	0.0	25.000	0.3746	2.0	4.31
	VATT	V	2× 240.0	1.586	0.0	25.000	0.3746	1.8	4.31
	VATT	R	2× 180.0	1.657	0.0	25.000	0.3746	1.5	4.31
NGC 6782	HST	F255W	3× 466.7	0	151.206	17.037	0.0996	0.04	3/4.15
	HST	F300W	3× 500.0	0	151.206	19.433	0.0996	0.04	3/4.15
	HST	F814W	2× 130.0	0	151.206	21.659	0.0996	0.08	3/4.15
	CTIO 0.9m	U	2×2400.0	1.154	0.0	---	0.396	2.09	4.15
	CTIO 0.9m	B	4× 450.0	1.321	0.0	---	0.396	1.59	4.15
	CTIO 0.9m	V	3× 300.0	1.399	0.0	---	0.396	1.37	4.15
	CTIO 0.9m	R	3× 200.0	1.448	0.0	---	0.396	1.38	4.15
	CTIO 1.5m	J	2× 20.0	---	0.0	---	0.645	1.33	4.15
	CTIO 1.5m	H	2× 10.0	---	0.0	---	0.645	1.31	4.15
	KPNO 2.2m	K	...	---	0.0	---	1.09	1.72	4.15
NGC 7685	HST	F300W	2× 900.0	0	64.488	19.433	0.0996	0.04	3/4.14
	HST	F814W	2× 100.0	0	64.488	21.659	0.0996	0.08	3/4.14
	VATT	U	2× 600.0	1.261	0.0	---	0.3746	1.59	4.14
	VATT	B	1× 300.0	1.286	0.0	---	0.3746	1.39	4.14
	JKT	V	1× 346.8	1.102	0.0	22.322	0.30	1.39	4.14
	JKT	R	1× 289.0	1.106	0.0	22.558	0.30	1.63	4.14
	JKT	I	1× 289.0	1.114	0.0	21.833	0.30	1.21	4.14
	UKIRT	K	8× 75.0	1.057	0.0	20.018	0.30	1.55	4.14
NGC 7769 (Mrk 9005)	HST	F300W	2× 900.0	0	64.927	19.433	0.0996	0.04	3/4.12
	HST	F814W	2× 100.0	0	64.927	21.659	0.0996	0.08	3/4.12
	VATT	U	2× 600.0	1.025	0.0	---	0.3746	1.42	4.12
	VATT	B	2× 300.0	1.026	0.0	---	0.3746	1.34	4.12
	VATT	V	1× 300.0	1.086	0.0	---	0.3746	0.97	4.12
	VATT	R	1× 300.0	1.059	0.0	---	0.3746	1.10	4.12
	JKT	I	1× 404.6	1.035	0.0	21.709	0.30	1.36	4.12
	UKIRT	H	5× 60.0	1.000	0.0	20.500	0.30	1.41	4.12

NOTES ON TABLE COLUMNS: (1) galaxy name; (2) telescope that produced the listed images; (3) filter: HST/WFPC2 (see Biretta et al. 2000), UIT (see Stecher et al. 1997; 150nm denotes both B1 and B2, 250nm both A1 and A5 filters), or ground-based Johnson UBV and Kron-Cousins RIJHK; (4) total exposure time, given as the number of independent integrations times the single image exposure time (as listed in the FITS headers and corresponding to the zero-points listed in Col. 7). For unequal length exposures, the listed single-exposure time is the mean of the actual exposure times; (5) average airmass of the image stack (0 for space-based observations); (6) image orientation. For HST, this is angle `PA_V3` (measured from North through East) of the V3 axis (i.e., the X = Y diagonal of the WFC3 CCD + 180°). For UIT and ground based images, the P.A. of the Y-axis of the CCD image is given (i.e., P.A. = 0 means that North is up and East is to the left); (7) photometric zero-point ZP derived for the ground-based images using: Vega-mag = ZP -2.5 log₁₀(DN / t), with DN the total object flux, and t in sec (see Col. 4). For HST/WFPC2, these are the Holtzman et al. (1995) Vega zero-points, and for UIT, ZP_ST = -2.5 log₁₀ C - 21.1, with C the calibration constants C_NUV and C_FUV listed in Stecher et al. (1997). We only list available and confirmed zero-points, but will update the FITS headers in the public data base as ground-based calibrations become available (see Taylor et al. 2002); (8) image pixel scale; (9) estimated FWHM of the relevant image PSF in arcsec. For HST images, these are not to be confused with the 0.0996" WFC pixel scale, and are derived as FWHM = 206265" × 1.22 × _cent / D, with the central wavelength of the filter (see text) in m and primary aperture D = 2.4 m. Note that especially the WFPC2 UV images are badly under-sampled. Micro-roughness of the HST mirror limits the mid-UV PSF to ~ 0.04" FWHM. For ground-based images, the FWHM values were measured using unsaturated stellar objects in each image as identified using `SExtractor`; (10) number of the figure(s) displaying each image.

2.3.3. Archival HST Images in Additional Filters

Several of the galaxies in the present sample have been observed with HST in filters other than F300W and F255W, or with instruments other than WFPC2. Maoz et al. (1996), for example, imaged the central 22" × 22" in 110 nearby galaxies in the mid-UV (2300Å) using the Faint Object Camera (FOC). The red-leak in the FOC mid-UV filters, however, is more severe (~ 24%; Keel & Windhorst 1993) than that in the WFPC2 filters ( appeq 5-7%; see Section 2.4.3), and the FOV is much smaller. Sixteen of our objects have been observed in other WFPC2 filters before - generally in a heterogeneous mixture of filters: F170W (far-UV), F336W, F439W, F555W, F606W, F702W, and/or some additional F814W images. These data are summarized in Table 3. In the archival WFPC2 exposures, the galaxy nucleus was often placed in the Planetary Camera (PC), which due to its smaller pixel size is less suited for accurate surface-photometry. Also, for galaxies ~ 1 in extent, more of a galaxy tends to be lost outside WFPC2's FOV when its nucleus is placed in the PC. We will study these Archival WFPC2 images in the other filters, where appropriate, in future papers.

**Table 3.** Other imaging data in the *HST* Archive on our Cycle 9 galaxy sample.

Object	Filter	_c		Exposure time	Orient	Proposal ID	PI	Note
		(Å)	(Å)	(sec)	(deg)
(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)

--- WFPC2 Images:
ESO 418-G008	F606W	5957	1508	2×80	227.216	SNAP 5446	G. Illingworth	center in PC1
	F814W	7940	1531	2×600	16.701	SNAP 8599	T. Boeker	PC1
NGC 1510	F170W	1730	500	2×400	303.570	GO 6716	T. Stecher
	F336W	3344	381	2×260	303.570	""	""
	F555W	5407	1236	1×200	303.570	""	""
	F814W	7940	1531	1×200	303.570	""	""
UGC 03426	F606W	5957	1508	1×500	73.315	SNAP 5479	M. Malkan	PC1
IC 2184	F555W	5407	1236	1×700+1×400	94.381	GTO 6870	J. Trauger
	F814W	7940	1531	2×600	94.381	""	""
UGC 05101	F814W	7940	1531	2×400	321.786	SNAP 6346	K. Borne
NGC 3310	F606W	5957	1508	1×500	280.821	SNAP 5479	M. Malkan	PC1
	F336W	3344	381	2×500	350.875	GO 6639	G. Meurer	PC1
	F439W	4300	475	2×300	350.875	""	""
	F814W	7940	1531	1×160+1×180	350.875	""	""
MCG+06-24-047	F814W	7940	1531	2×700	53.898	GO 5370	R. Griffiths	WF4 and PC1
NGC 3516	F606W	5957	1508	1×500	218.572	SNAP 5479	M. Malkan	PC1; core saturated
	F300W	2911	745	2×400	344.525	SNAP 6355	M. Giavalisco	PC1
	F547M	5479	486	2×70	28.496	GO 6419	A. Wilson	PC1
	F791W	7829	1218	2×70	28.465	""	""
	F450W	4520	958	1×900+1×1400	12.393	GO 6633	C. Carollo	PC1
	F555W	5407	1236	1×300+1×700	12.393	""	""
	F814W	7940	1531	1×230+1×500	12.393	""	""
NGC 3690/IC 694	F606W	5957	1508	1×500	177.915	SNAP 5479	M. Malkan	PC1
	F336W	3344	381	4×400	142.669	GO 6639	G. Meurer	PC1
	F439W	4300	475	2×200+2×260	142.669	""	""
	F814W	7940	1531	2×40+160+260	142.669	""	""
	F555W	5407	1236	2×350	306.258	SNAP 8602	A. Filippenko	PC1
	F814W	7940	1531	2×350	356.266	""	""
	F814W	7940	1531	2×350	293.276	""	""
UGC 06527	F606W	5957	1508	1×500	157.556	SNAP 5479	M. Malkan	PC1
NGC 3921	F336W	3344	381	2×600	172.058	GO 5416	B. Whitmore	PC1
	F555W	5407	1236	1×30+2×1200	172.058	""	""
	F814W	7940	1531	1×30+2×900	172.058	""	""
	F555W	5407	1236	2×400+2×500	321.026	GO 7466	J. Charlton	targets tidal tails
	F814W	7940	1531	2×400+2×400	321.026	""	""
NGC 4478	F814W	7940	1531	1×1200+1×2400	299.972	GO 5369	R. Griffiths
	F606W	5957	1508	6×2800	299.972	GTO 6252	E. Groth	saturated center and star
	F814W	7940	1531	5×2800+1×2500	299.972	""	""	""
	F300W	2911	745	1×100	293.598	GO 6253	J. MacKenty
	F606W	5957	1508	3×2800	291.727	GTO 6254	E. Groth	saturated center and star
	F814W	7940	1531	2×1700	291.727	""	""	""
	F702W	6895	1389	1×300+1×700	325.004	SNAP 6357	W. Jaffe	PC1
	F555W	5407	1236	4×400	291.943	GO 6587	D. Richstone	PC1
	F814W	7940	1531	2×800	291.943	""	""
NGC 5253	F606W	5957	1508	1×500	131.324	SNAP 5479	M. Malkan	PC1
	F255W	2553	393	3×800+3×800+3×700	264.709	GO 6124	R. Fesen
	F547M	5479	486	2×200+2×600	264.460	GO 6524	D. Calzetti
	F656N	6563	21	2×500+1100+1500	264.460	""	""
	F814W	7940	1531	2×180+2×400	264.460	""	""
	F487N	4866	26	3×1300+1×1200	264.460	""	""
	F170W	1730	500	2×400	280.005	GO 6716	T. Stecher	PC1
	F336W	3344	381	2×260	280.005	""	""
	F555W	5407	1236	1×200	280.005	""	""
	F814W	7940	1531	1×200	280.005	""	""
	F502N	5013	27	200+260+600+800	259.612	GO 9144	D. Calzetti
	F673N	6732	47	2×600+1×1200	259.612	""	""
UGC 08696	F814W	7940	1531	2×400	343.721	SNAP 6346	K. Borne	PC1
	F814W	7940	1531	2×400	20.558	""	""	WF3
UGC 08823	F606W	5957	1508	1×500	182.130	SNAP 5479	M. Malkan	PC1; core saturated
NGC 6789	F336W	3344	381	2×1400	303.896	GO 8122	R. Schulte-Ladbeck	PC1
	F555W	5407	1236	2×1300+4×1400	303.896	""	""
	F656N	6563	21	2×1400	303.896	""	""
	F814W	7940	1531	2×1300+4×1400	303.896	""	""
NGC 6782	F450W	4520	958	3×300	151.212	GO/DD 8550	K. Noll
	F606W	5957	1508	2×160	151.212	""	""
	F814W	7940	1531	2×160	151.212	""	""
--- NICMOS Images:
UGC 05101	F110W	11285	1632	1×112	107.171	GTO 7219	N. Scoville	NIC2
	F160W	16060	1177	1×112	107.171	""	""	""
	F220M	22182	512	1×136	107.171	""	""	""
NGC 3310	F110W	11292	1654	1×128	125.84	GO 7268	R. van der Marel	NIC1
	F110W	11285	1632	1×160	125.84	""	""	NIC2
	F160W	16071	1170	2×256	125.84	""	""	NIC1
	F160W	16060	1177	1×128+1×192	125.84	""	""	NIC2
	F160W	16078	1172	1×128+1×256	125.84	""	""	NIC3
	F205W	20714	1832	1×256	125.84	""	""	NIC2
NGC 3516	F160W	16060	1177	1×704	251.013	SNAP 7330	J. Mulchaey	NIC2
NGC 3690/IC 694	F110M	11026	590	8×128	133.864	GTO 7218	M. Rieke	NIC1; mosaic of 8 pointings
	F160W	16060	1177	2×104	133.851	""	""	NIC2; 2 pointings
	F166N	16583	59	1×256	133.901	""	""	NIC3
	F187N	18748	67	4×640	133.851	""	""	NIC1; mosaic of 4 pointings
	F187N	18740	68	2×160	133.851	""	""	NIC2; 2 pointings
	F190N	18986	73	4×640	133.842	""	""	NIC1; mosaic of 4 pointings
	F190N	19003	63	2×160	133.851	""	""	NIC2; 2 pointings
	F212N	21213	89	1×1280+1×1408	133.851	""	""	""; 2 pointings
	F237M	23696	473	2×288	133.851	""	""	""; 2 pointings
	F215N	21487	80	1×1408+1×1408	133.842	""	""	""; 2 pointings
	F222M	22182	512	2×176	133.842	""	""	""; 2 pointings
UGC 06527	F160W	16060	1177	1×256	39.150	SNAP 7328	M. Malkan	NIC2
NGC 3921	F110W	11285	1632	1×160	63.944	GO 7268	R. van der Marel	NIC2
	F110W	11292	1654	1×128	63.948	""	""	NIC1
	F160W	16060	1177	1×192+1×128	63.944	""	""	NIC2; 2 pointings
	F160W	16078	1172	2×256+2×128+192	63.944	""	""	NIC3; mosaic of 4 pointings
	F205W	20714	1832	3×256	63.944	""	""	NIC2; 3 pointings
NGC 5253	F110W	11285	1632	1×24	105.339	GTO 7219	N. Scoville	NIC2
	F187N	18740	68	1×64	105.339	""	""	""
	F160W	16060	1177	1×24	105.339	""	""	""
	F190N	19003	63	1×64	105.339	""	""	""
	F222M	22182	512	1×80	105.339	""	""	""
	F160W	16071	1170	3×384+2×640	296.776	GO 7849	W. Freedman	NIC1
	F160W	16060	1177	3×384+2×640	296.776	""	""	NIC2
UGC 08696	F110W	11285	1632	1×64	133.577	GTO 7219	N. Scoville	NIC2
	F160W	16060	1177	1×64	133.577	""	""	""
	F222M	22182	512	1×80	133.577	""	""	""
--- FOC Images:
UGC 03426	F210M	2156	214	1×596	274.030	GTO 5140	F. Macchetto
	F320W	3360	844	1×596	274.030	""	""
	F342W	3410	702	1×597	277.678	""	""
	F372M	3710	406	1×896	274.030	""	""
	F502M	4940	530	1×750	274.030	""	""
	F550M	5460	188	1×1196	274.030	""	""
	F502M	4940	530	3×5262	289.829	GO 5918	D. Axon	imaging polarimetry
	F275W	2770	594	3×5187	20.342	GO 6702	L. Kay	imaging polarimetry
	F342W	3410	702	3×1697	20.342	""	""
IC 2184	F220W	2280	480	1×996	120.036	GO 4800	P. Conti	pre-refurbishment
NGC 3310	F220W	2280	480	1×197	13.102	GO 3591	T. Heckman	pre-refurbishment
NGC 3690/IC 694	F220W	2280	480	1×897	333.653	GO 3591	T. Heckman	pre-refurbishment
	F220W	2280	480	2×896+2×896	269.868	GO 3792	S. Neff	""; 2 pointings
NGC 5253	F220W	2280	480	1×497	122.891	GO 3591	T. Heckman	pre-refurbishment

Where Archival NICMOS images in the F110M/F110W, F160W or F222M filters are available (GTO 7218, PI: Rieke, see e.g., Alonso-Herrero et al. 2000; GTO 7219, PI: Scoville, see Scoville et al. 2000; GO 7268, PI: van der Marel, see Ravindranath et al. 2001; SNAP 7328, PI: Malkan, see Quillen et al. 2001; SNAP 7330, PI: Mulchaey, see Regan & Mulchaey 1999) we use them in lieu of ground-based JHK data in Table 2 and Fig. 4.