All Tables

Table 1: The integrated properties of our sample of 9 blue LSBGs. The morphological types have been determined by Rönnback & Bergvall (1994). Absolute magnitudes are based on distances derived from the model by Schechter (1980), assuming a distance to the Virgo cluster of 17 Mpc and a Hubble constant of H₀=75 km s^-1 Mpc^-1. Unless stated otherwise, m_B represents the integrated B-band magnitude inside the $\mu _{B,0}$ = 26.5 mag arcsec^-2 isophote. Here, $\mu _0$ represents the "true'' central surface brightness and $\mu ^D_0$ the central surface brightness of the disk extrapolated to the centre. Both have been corrected for inclination assuming an infinitely thin disk. $\it BVR$ are in the Cousins system and $\it JHK'$ in the Johnson system, while i is in the Thuan-Gunn system. All magnitudes have been corrected for galactic extinction (Burstein & Heiles 1982). EW represents the equivalent width of the H $\alpha$ emission line. All photometric data come from Rönnback & Bergvall (1994) and Bergvall et al. (1999), except the $\langle$ B-R $\rangle$ entries, which come from the ESO/Uppsala survey (Lauberts & Valentijn 1989).
Table 2: The grid of Z01 evolutionary sequences. All sequences assume $Z_{{\rm gas}}=Z_{{\rm stars}}$ , a gas covering factor of 1.0, a hydrogen number density of 100 cm^-3 and the IMF slope, $\alpha$ , to be valid throughout the stellar mass range 0.08-120 $M_\odot$ . The grid consists of all possible combinations of the parameter values listed below. In addition to these, 108 sequences with $M_{{\rm up}}=40~M_\odot$ were generated for test purposes with variations in IMF slope, metallicity, star formation history and redshift, but with fixed $M_{{\rm tot}}=10^9~M_\odot$ and filling factor 0.01.
Table 3: The grid of PÉGASE.2 evolutionary sequences. All sequences assume the IMF slope, $\alpha$ , to be valid throughout the stellar mass range 0.08-120 $M_\odot$ . The grid consists of all possible combinations of the parameter values listed below. The abbreviations used are described in Table 2.
Table 4: The range in age, M/L_V and $M_\star$ allowed by the acceptable fits to the observations at the $1\sigma$ and $2\sigma$ levels using the Z01 grid of evolutionary sequences defined in Table 2 and the PÉGASE.2 grid of evolutionary sequences defined in Table 3. Only the results from sequences assuming a Salpeter IMF with $M_{\rm up}=120~M_\odot$ have been included. Missing entries indicate the lack of acceptable fits at a given confidence level or, in the case of $M_\star$ , the lack of redshift data for a particular object. To obtain values of M/L_V and $M_\star$ consistent with the observed IMF of Kroupa (2001), these values should be multiplied by a factor of $\approx$ 0.6, as discussed in Sect. 4.3.
Table 5: The allowed range of stellar M/L ratios among the blue LSBGs in our sample for which the Z01 and PÉGASE.2 models are able to provide adequate fits at levels of $1\sigma$ and $2\sigma$ , respectively. Only the results from model sequences assuming a Salpeter IMF with $M_{\rm up}=120~M_\odot$ have been used. Here, the BVRI filters are in the Cousins system and $\it JHK$ in the Johnson system, while i is in the Thuan-Gunn system. To obtain values of M/L consistent with the IMF of Kroupa (2001), these values should be multiplied by a factor of $\approx$ 0.6, as discussed in Sect. 4.3.