PO/LCO Atlas of BCDs - Gil de Paz et al.

2. SAMPLE

The galaxies in our sample have been selected from several exploratory studies including the Markarian lists (Mrk - Markarian, Lipovetskii, & Stepanian 1981), Second Byurakan (SBS - Markarian, Stepanian, & Erastova 1986), University of Michigan (UM - MacAlpine & Williams 1981), Palomar Objective-prism X (POX - Kunth, Sargent, & Kowal 1981), Hamburg/SAO (HS - Ugryumov et al. 1999), Universidad Complutense de Madrid (UCM - Zamorano et al. 1994, 1996; Alonso et al. 1999), and Tololo (Tol - Smith, Aguirre, & Zemelan 1976) surveys, as well as the lists of Zwicky & Zwicky (1971), and Haro (1956). Mrk and SBS galaxies were originally selected by their ultraviolet excess on photographic plates taken with the objective-prism tecnique. POX, HS, UM, UCM, & Tol galaxies were discovered by the presence of emission lines, [OIII] lambda 5007Å (UM, HS, & Tol), H alpha (UCM), or both (POX), in objective-prism spectra. Finally, galaxies in the lists of Zwicky & Zwicky (1971) and Haro (1956) were selected according to their compactness and blue colors as inferred from photographic plates taken through 3 different filters (blue, red, & infrared).

From the list of BCD galaxies discovered in these surveys we have selected objects with heliocentric recession velocities lower than 4000 km s^-1. This limit was set by the longest-wavelength H alpha filter (PO 6640) available within the Palomar Observatory narrow-band filters set. Our sample also includes the six Virgo Cluster BCDs analyzed by Popescu et al. (2002) and the highly obscured Local Group galaxy IC 10. Although this latter galaxy has been ordinarily classified as a dwarf irregular, the recent study of Richer et al. (2001) shows that its structural properties resemble more those of BCD galaxies (see Papaderos et al. 1996a). Our final sample consists of 114 galaxies.

It is worth mentioning that this sample does not include all the galaxies classified as BCDs in those surveys (noteworthy missing objects are UM 461, UM 462, or UM 465). Our sample cannot either be considered a complete sample since it has been selected from surveys that used different techniques and, therefore, are affected by different selection criteria.

In Table 1 we summarize the basic properties of the galaxies in this Atlas. In the few cases where the distance to the galaxy had been determined by measuring the magnitude of the tip of the RGB we adopted the distance value given by this method (see Lee, Freedman, & Madore 1993). In the vast majority of the cases we computed the distance using the Galactic Standard of Rest velocity of the galaxies assuming a Hubble constant of 70 km s^-1Mpc^-1 (Freedman et al. 2001). Distances to the galaxies in the Virgo Cluster were adopted to be 16Mpc (Macri et al. 1999). For 49 galaxies with published data the [NII] lambda 6584 Å / H alpha line ratios required to correct the H alpha fluxes measured from the [NII] lambda lambda 6548,6584 Å doublet contamination were taken from Guseva, Izotov, & Thuan (2000), Izotov & Thuan (1999), Terlevich et al. (1991), Kennicutt (1992), Vílchez (1995), Masegosa, Moles, & Campos-Aguilar (1994), Kobulnicky & Skillman (1998), Kniazev et al. (2001), van Zee et al. (1998a), Hunter & Hoffman (1999), Steel et al. (1996), Vacca & Conti (1992), Thuan, Izotov, & Lipovetsky (1995), Popescu & Hopp (2000), Garnett (1990), Thuan, Izotov, & Foltz (1999), Jansen et al. (2000), Rego et al. (1998), and Augarde et al. (1990). In those cases where the [NII] lambda 6584 Å / H alpha line ratio was not available we adopted an average value of 0.055 computed using the 49 galaxies in our sample that do have [NII] lambda 6584 Å / H alpha data. For comparison the average value obtained by Hunter & Hoffman (1999) for the BCDs in their sample was 0.091.

Equatorial coordinates, Galactic extinction (A_B) and heliocentric radial velocity values for the sample were taken from NED (see Table 1). Galactic extinction data are derived from the 100µm maps of Schlegel, Finkbeiner, & Davis (1998). The values obtained are typically smaller than A_B = 0.5 mag, except for IC 10 (6.2 mag), II 40 (3.5mag), and NGC 2915 (1.2 mag). In the case of IC 10 the very low Galactic latitude makes the foreground extinction correction very uncertain.

**Table 1.** Sample

Object Name	RA₂₀₀₀	DEC₂₀₀₀	A_B	v_helio	_H	H filter	Distance	[NII] / H
	(h m s)	° ' ")	(mag)	(km/s)	(Å)		(Mpc)
(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)

IC 10 ⁽¹⁾	00 20 17.3	+59 18 14	6.16	-348	6555.2	PO 6563	1.0	0.045
HS 0029+1748	00 32 03.1	+18 04 46	0.57	2188	6610.7	PO 6614	33.3	0.055:
Haro 14	00 45 46.4	-15 35 49	0.09	944	6583.5	PO 6584	14.0	0.093
UM 285	00 51 58.8	-01 40 18	0.24	1900	6604.4	PO 6601	28.2	0.055:
UCM 0049-0045	00 51 59.6	-00 29 12	0.17	1633	6598.5	PO 6593	24.4	0.055:
UM 323	01 26 46.6	-00 38 46	0.13	1923	6604.9	PO 6601	28.3	0.055:
Mrk 996	01 27 35.5	-06 19 36	0.19	1622	6598.3	PO 6593	23.7	0.057
UM 133	01 44 41.3	+04 53 26	0.16	1623	6598.3	PO 6593	24.1	0.055:
UM 382	01 58 09.4	-00 06 38	0.12	3526	6639.9	PO 6640	50.9	0.055:
UM 404	02 10 12.2	-01 24 49	0.15	3598	6641.6	PO 6640	51.8	0.055:
KUG 0207-016A	02 10 09.8	-01 24 03	0.15	3523	6639.9	PO 6640	50.7	0.055:
UM 408	02 11 23.5	+02 20 31	0.15	3598	6641.6	PO 6640	51.9	0.039
UM 417	02 19 30.3	-00 59 13	0.14	2698	6621.9	PO 6614	38.9	0.055:
Mrk 370	02 40 29.0	+19 17 50	0.40	790	6580.1	PO 6584	12.2	0.055:
Mrk 600	02 51 04.6	+04 27 14	0.28	1008	6584.9	PO 6584	14.6	0.025
NGC 1522	04 06 07.7	-52 40 09	0.06	905	6582.6	LC 6570	10.6	0.055:
NGC 1705 ⁽²⁾	04 54 13.7	-53 21 41	0.04	628	6576.5	LC 6570	5.1	0.055:
II Zw 33	05 10 48.1	-02 43 00	0.45	2850	6625.2	PO 6624	39.4	0.070
II Zw 33B	05 10 45.2	-02 45 31	0.44	2870	6625.6	PO 6624	39.7	0.055:
II Zw 40	05 55 42.8	+03 23 30	3.54	789	6580.1	PO 6584	9.8	0.024
Tol 0610-387	06 12 13.7	-38 46 26	0.33	1799	6602.2	LC 6600	22.8	0.055:
Mrk 0005	06 42 15.5	+75 37 33	0.36	792	6580.1	PO 6584	13.2	0.058
Mrk 0007	07 28 12.0	+72 34 29	0.13	3060	6629.8	PO 6624	45.4	0.055:
Mrk 86 ⁽³⁾	08 13 14.7	+45 59 26	0.23	447	6572.6	PO 6570	6.9	0.154
HS 0822+3542	08 25 55.4	+35 32 32	0.20	732	6578.8	PO 6584	10.1	0.005
UGC 4483 ⁽⁴⁾	08 37 03.0	+69 46 50	0.15	178	6566.7	PO 6563	3.2	0.055:
UGC 4703N1	08 58 29.8	+06 19 17	0.30	3551	6640.5	LC 6630	48.8	0.151
UGC 4703N2	08 58 27.4	+06 20 06	0.29	3536	6640.2	LC 6630	48.6	0.151
Mrk 1416	09 20 56.2	+52 34 05	0.07	2326	6613.7	PO 6614	33.8	0.055:
Mrk 108	09 21 30.3	+64 14 20	0.24	1534	6596.4	PO 6593	21.8	0.032
Mrk 400	09 26 01.2	+19 23 01	0.15	2522	6618.0	PO 6614	34.8	0.055:
NGC 2915 ⁽⁵⁾	09 26 11.5	-76 37 36	1.18	468	6573.0	LC 6570	3.6	0.055:
I Zw 18 ⁽⁶⁾	09 34 02.0	+55 14 28	0.14	751	6579.2	PO 6584	12.6	0.016
Mrk 1418	09 40 27.1	+48 20 15	0.10	773	6579.7	PO 6584	11.4	0.055:
Mrk 1423	09 43 01.6	+58 58 25	0.07	1358	6592.5	PO 6593	20.4	0.055:
SBS 0940+544C	09 44 16.7	+54 11 33	0.05	1638	6598.7	PO 6593	24.1	0.006
Mrk 709	09 49 18.0	+16 52 46	0.15	1197	6589.0	PO 6593	15.7	0.098
Mrk 1426	09 49 18.3	+48 33 50	0.06	1835	6602.9	PO 6601	26.6	0.055:
UGCA 184	09 49 30.4	+55 34 49	0.04	1551	6596.8	PO 6593	23.0	0.023
Mrk 409	09 49 41.2	+32 13 16	0.07	1527	6596.2	PO 6593	21.3	0.055:
Tol 001	09 56 14.9	-29 36 21	0.40	1839	6603.0	LC 6600	23.2	0.055:
Tol 002	09 59 20.7	-28 07 54	0.40	710	6578.3	LC 6570	7.1	0.047
NGC 3125	10 06 33.6	-29 56 09	0.33	865	6581.7	LC 6570	9.3	0.030
SBS 1006+578	10 09 55.0	+57 36 00	0.04	1512	6595.9	PO 6593	22.5	0.055:
Haro 2	10 32 31.9	+54 24 03	0.05	1461	6594.8	PO 6593	21.6	0.220
Mrk 1434	10 34 10.1	+58 03 49	0.03	2269	6612.5	PO 6614	33.4	0.055:
Haro 3	10 45 22.4	+55 57 37	0.03	944	6583.5	PO 6584	14.4	0.063
SBS 1054+504	10 56 58.7	+50 08 26	0.07	1358	6592.5	PO 6593	20.1	0.055:
Haro 4	11 04 58.5	+29 08 22	0.13	646	6576.9	PO 6570	8.8	0.018
VII Zw 403 ⁽⁷⁾	11 27 59.9	+78 59 39	0.16	-100	6560.6	PO 6563	4.8	0.055:
Mrk 178 ⁽⁸⁾	11 33 29.1	+49 14 17	0.08	249	6568.3	PO 6563	4.2	0.021
UM 439	11 36 36.9	+00 49 01	0.11	1099	6586.8	PO 6584	14.0	0.015
Mrk 1450	11 38 35.6	+57 52 27	0.04	946	6583.5	PO 6584	14.7	0.025
UM 452	11 47 00.7	-00 17 39	0.14	1478	6595.1	PO 6593	19.5	0.100
SBS 1147+520	11 49 54.4	+51 44 11	0.10	1257	6590.3	PO 6593	18.9	0.055:
Tol 17	11 50 03.0	-28 40 17	0.33	2099	6608.7	LC 6600	27.4	0.050
UM 455	11 50 23.7	-00 31 43	0.11	3863	6647.3	LC 6630	53.6	0.055:
UM 456	11 50 36.2	-00 34 02	0.12	1757	6601.2	LC 6600	23.5	0.055:
UM 456A	11 50 34.0	-00 32 16	0.12	1831	6602.9	LC 6600	24.5	0.055:
Pox 4	11 51 11.6	-20 36 02	0.17	3589	6641.3	LC 6630	48.9	0.014
ESO 572-G025	11 57 28.0	-19 37 27	0.21	1781	6601.8	LC 6600	23.1	0.055:
VCC 0001 ⁽⁹⁾	12 08 20.3	+13 41 03	0.14	2267	6612.4	PO 6614	16.0	0.055:
Mrk 1313	12 12 14.7	+00 04 20	0.11	2328	6613.8	PO 6614	31.8	0.030
VCC 0130 ⁽⁹⁾	12 15 04.0	+09 45 13	0.07	2189	6610.7	LC 6600	16.0	0.055:
Haro 8 ⁽⁹⁾	12 19 09.9	+03 51 21	0.07	1526	6596.2	PO 6593	16.0	0.055:
UM 491	12 19 53.1	+01 46 24	0.10	2025	6607.1	PO 6601	27.6	0.055:
ISZ 399	12 19 59.5	-17 23 31	0.25	900	6582.5	LC 6570	10.8	0.055:
VCC 0459 ⁽⁹⁾	12 21 11.2	+17 38 18	0.15	2107	6608.9	LC 6600	16.0	0.055:
VCC 0655 ⁽⁹⁾	12 23 37.5	+17 32 27	0.15	1142	6587.8	LC 6600	16.0	0.055:
Tol 65	12 25 46.9	-36 14 01	0.32	2698	6621.8	LC 6630	36.0	0.007
VCC 0848 ⁽⁹⁾	12 25 52.5	+05 48 33	0.10	1537	6596.4	LC 6600	16.0	0.055:
Mrk 209 ⁽¹⁰⁾	12 26 16.0	+48 29 37	0.06	281	6569.0	PO 6563	5.8	0.010
Mrk 1329 ⁽⁹⁾	12 37 03.0	+06 55 36	0.10	1632	6598.5	PO 6593	16.0	0.026
UGCA 290 ⁽¹¹⁾	12 37 21.8	+38 44 38	0.06	445	6572.5	PO 6570	6.7	0.055:
VCC 1750 ⁽⁹⁾	12 38 15.5	+06 59 39	0.09	-117	6560.2	LC 6570	16.0	0.055:
Haro 9	12 45 17.1	+27 07 32	0.06	1069	6586.2	PO 6584	15.3	0.220
NGC 4861	12 59 01.8	+34 51 40	0.04	847	6581.3	PO 6584	12.6	0.042
UM 533	12 59 58.1	+02 02 59	0.11	886	6582.2	PO 6584	11.7	0.055:
Mrk 450	13 14 48.3	+34 52 51	0.06	863	6581.7	PO 6584	13.0	0.038
NGC 5058	13 16 52.3	+12 32 55	0.13	961	6583.8	PO 6584	13.4	0.055:
PGC 046448	13 19 22.2	-15 09 24	0.28	2832	6624.8	LC 6630	38.9	0.055:
Pox 186	13 25 48.6	-11 36 38	0.20	1170	6588.4	LC 6600	15.4	0.055:
Tol 35	13 27 06.5	-27 57 24	0.23	2023	6607.1	LC 6600	27.0	0.038
SBS 1331+493	13 33 22.9	+49 06 06	0.04	599	6575.9	PO 6570	9.9	0.037
Tol 85	13 37 08.2	-32 55 28	0.23	3598	6641.5	LC 6630	49.4	0.055:
Mrk 67	13 41 56.5	+30 31 10	0.08	958	6583.8	PO 6584	14.3	0.019
Mrk 1480	13 42 51.8	+52 42 31	0.05	1798	6602.2	PO 6601	27.2	0.055:
Mrk 1481	13 42 59.3	+52 41 18	0.04	1803	6602.3	PO 6601	27.3	0.055:
Tol 1345-420	13 48 22.2	-42 21 15	0.43	2398	6615.3	LC 6600	32.1	0.018
HS 1400+3927	14 02 36.1	+39 13 13	0.06	1396	6593.4	PO 6593	21.1	0.055:
SBS 1415+437	14 17 01.7	+43 30 13	0.04	609	6576.1	PO 6570	10.1	0.013
SBS 1428+457	14 30 12.2	+45 32 32	0.05	2360	6614.5	PO 6614	35.3	0.055:
Tol 1434+032	14 37 19.4	+03 03 01	0.15	1499	6595.6	PO 6593	21.4	0.055:
Mrk 475	14 39 05.4	+36 48 21	0.05	583	6575.6	PO 6570	9.7	0.055:
HS 1440+4302	14 42 15.9	+42 49 48	0.06	2548	6618.6	PO 6614	38.0	0.038
HS 1442+4250	14 44 12.1	+42 37 37	0.06	749	6579.2	PO 6584	12.3	0.055:
UCM 1446+2312	14 48 45.2	+22 59 34	0.14	2398	6615.3	PO 6614	35.2	0.055:
Tol 1448+116	14 50 22.7	+11 24 11	0.10	1870	6603.7	PO 6601	27.2	0.055:
II Zw 70	14 50 56.5	+35 34 18	0.05	1215	6589.4	PO 6593	18.7	0.048
II Zw 71	14 51 14.4	+35 32 31	0.06	1292	6591.1	PO 6593	18.7	0.114
I Zw 115	15 32 57.0	+46 27 07	0.06	656	6577.2	PO 6570	11.4	0.055:
SBS 1533+574	15 34 13.8	+57 17 06	0.06	3310	6635.3	PO 6640	49.6	0.055:
I Zw 123	15 37 04.2	+55 15 48	0.06	665	6577.4	PO 6570	11.7	0.033
HS 1609+4827	16 11 11.5	+48 20 04	0.06	2817	6624.5	PO 6624	42.6	0.055:
UCM 1612+1308	16 15 17.1	+13 01 32	0.21	3630	6642.3	PO 6640	53.2	0.026
UGCA 412	16 35 21.1	+52 12 53	0.12	2700	6621.9	PO 6624	41.1	0.055:
HS 1704+4332	17 05 45.4	+43 28 49	0.13	2076	6608.2	PO 6614	32.2	0.055:
NGC 6789 ⁽¹²⁾	19 16 41.9	+63 58 18	0.30	-141	6559.7	PO 6563	3.6	0.055:
Tol 1924-416	19 27 58.2	-41 34 32	0.38	2874	6625.7	LC 6630	41.0	0.024
Tol 1937-423	19 40 58.1	-42 15 44	0.34	2698	6621.8	LC 6630	41.8	0.055:
Mrk 900	21 29 59.6	+02 24 51	0.24	1152	6588.0	PO 6584	18.8	0.131
Mrk 314	23 02 59.2	+16 36 19	0.38	2081	6608.4	PO 6614	32.2	0.055:
Mrk 324	23 26 32.8	+18 15 59	0.22	1600	6597.8	PO 6593	25.3	0.051
Mrk 328	23 37 39.6	+30 07 47	0.40	1379	6593.0	PO 6593	22.4	0.221

Note. - Columns stand for: (1) Galaxy name. (2) Right Ascension (J2000) in (h m s). (3) Declination (J2000) in (° ' "). (4) B-band Galactic extinction in magnitudes (Schelegel et al. 1998). (5) Heliocentric radial velocity in kms^-1 (taken from NED). (6) Observed wavelength for H (Å). (7) Filter used for the H-line imaging. (8) Distance (Mpc). (9) [NII]6584Å / H intensity ratio. Values of 0.055: are estimated values only, adopted from the average of 49 other galaxies in the sample.
References. - For non-redshift distances: (1) Hunter (2001); (2) Tosi et al. (2001); (3) Sharina, Karachentsev, & Tikhonov (1999); (4) Dolphin et al. (2001); (5) Meurer et al. (1996); (6) Östlin (2000); (7) Schulte-Ladbeck et al. (1999); (8) Schulte-Ladbeck et al. (2000); (9) Virgo cluster (Macri et al. 1999); (10) Schulte-Ladbeck et al. (2001); (11) Crone et al. (2000); (12) Drozdovsky et al. (2001).