4 Wolf-Rayet galaxies

Some of our galaxies show the broad HeII ${\lambda}$4686 feature, which is a direct signature from Wolf-Rayet (WR) stars. For low resolution spectroscopy (as in the case of our spectra) this line is usually seen as a WR bump, a blend of HeII and other broad stellar emission lines from CIII, NIII and NV, but also of narrow nebular emission lines including HeII ${\lambda}$4686. The galaxies with detected WR features are listed in Table 8 with the flag D (detection), while a few more candidates for WR galaxies are also listed in Table 8, with the flag C (candidates). For some of the galaxies with detected WR features we also list the line ratios (corrected for internal extinction) relative to H${\beta }$ = 100. The first galaxy from the table, HS 0915+5540, does not belong to the spectrophotometric catalogue presented in this paper, but to the larger catalogue of emission-line galaxies from which the present catalogue was selected (Popescu et al. 1996).

 

 

Table 6:

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)
Galaxy	MB	z	F(H ${\alpha})_{{\rm obs}}$	[OII]	[OIII]	[NII]	[SII]	$r_{{\rm HII}}$	type
				3727	5007	6584	6724
			[ ${\rm erg}\,{\rm s}^{-1}\,{\rm cm}^{-2}$]				6731	[ $^{\prime\prime}$]
HS 1309+3409	-20.19	0.0785	1.59e-14	-	-	41	14	1.5	SBN
HS 1331+3906	-20.37	0.0643	1.11e-14	-	-	37	33	2.4	SBN
HS 1336+3650	-16.84	0.0202	3.16e-15	-	114	-	-	1.5	DHIIH
HS 1421+4018	-	0.0982	6.12e-15	132	-	-	84
HS 1435+4523	-20.29	0.1267	8.69e-15	60	22	26	65	1.9	SBN
HS 1505+3944	-18.47	0.0366	5.20e-15	40	-	-	-	2.8	DANS/IP
HS 1522+4214	-17.76	0.0190	3.74e-15	79	31	29	55	1.85	DANS/DHIIH

In total we detected 6 new WR galaxies and 3 candidates for WR galaxies. This represent 5.5$\%$ from our spectrophotometrical catalogue, or 9$\%$, if we include the candidates, too. Such a detection rate is somewhat lower than the detection rate of 10$\%$ obtained by Masegosa et al. (1991) for a systematic search for broad WR bump in the HII galaxies. However our spectral resolution is very low and it is therefore not optimised for this kind of search, and these results came only serendipitously.

The total number of known WR galaxies and extragalactic HII regions showing broad HeII ${\lambda}$4686 emission is 139 (from the recent compilation of Schaerer et al. 1999). These objects are found among a large variety of morphological types, from BCDs and Im galaxies to massive spirals and luminous IRAS galaxies, and even in Seyfert 2 and LINERSs (Osterbrock & Cohen 1982; Kunth & Contini 1998). Extending the sample of WR galaxies is very useful in constraining the evolution of massive stars and the parameters of the upper part of the IMF. Also, as discussed by Schaerer et al. (1999), WR galaxies represent useful templates of young starburst galaxies, which may be used to explain the properties of the distant star-forming galaxies.

Among the galaxies with detected WR features we found one SBN galaxy (HS 1657+5735), a DANS galaxy (HS 0915+5540), three DHIIH galaxies (HS 1312+3508,
HS 1424+3836, HS 1507+3743), and a interacting pair, IP (HS 1304+3529). The candidates for WR features are SS, HIIH and DHIIH galaxies. Thus it is probably reasonable to conclude that WR phenomenon is spread over all morphological subtypes of BCDs.