1. Jaime Izquierdo, Jesús Gallego, Jaime Zamorano Dpto. Astrofísica y CC. de la Atmósfera, Universidad Complutense de Madrid Flux-weighted virial masses from emission lines as a tracer of stellar masses for star-forming galaxies The UCM survey Sample of galaxies with active stellar formation in the Local Universe selected by Hα emission Calar Alto, Schmidt 80/120 cm (1950 Å/mm). 471.4  (0.4 ELGs/  ) 191 galaxias z 20 Å. r Ha -Stellar formation galaxies identification -Stellar formation rate -Luminosity Function -Morfology -Fisical Properties :  Stellar Mass Aims Data and Observations TelescopINT 2,5m InstrumentIDS-500mm DetectorTEK #3 Spatial scale0,33 arcsec/píxel Spectral Resolution1,2 Å Anchura de la rendija1 arcsec Run MAY97 AGO98 DEC07 MAR08 Observed galaxies 45 83 47 29 175 in Total “Disk-like” Galaxies Low excitation High metalicity Virial Mass M v = C 2 σ 2 Re C 2 constant Re efectiv radio (kpc) Flux-weighted virial Mass σΣi (Fi σi) / Σfi σi velocity dispersion Colapsed Virial Mass σobtained from colapsed spectra This research provides a relationship between virial and stellar masses We have obtained a calibration applicable to futures galaxies surveys at different z: logMe=0.808 logMvF+ 1.794 (Chabr.) logMe=0.804 logMvF+2.084 (Salpet.) Conclusions Dynamical masses of the galaxies studied in this work, are consistent with the stellar masses photometrically estimated by Pérez-González (2013) We have demonstrated that the rotation curve by Hα emission line is enough good accuracy with the real galaxy rotation curve. Dynamical masses obtained are lower than virial masses. There are no evidence of any reason. A motive could be that this galaxies present a starburst in the nuclei that control the velocity dispersion obtained from the spectra. We have demonstrated the utility of the stellar and virial masses methods to calculate the mass of a sample of galaxies. - Star-forming Galaxy Masses of the Local Universe. - Virial Masses from the cinematic of ionized gas. - Dynamical Masses from rotational curves. - Calibration applicable to futures galaxies surveys at different z. - Comparison with stellar masses photometrically estimated by Pérez-González (2003 Doctoral Thesis). “HII-like” Galaxies High excitation Low metalicity Δ V rot velocidad de rotación (km/s) Δ R distancia al centro (kpc) M d = Δ V 2 rot Δ R / G Dynamical Mass UCM 2304+1640 UCM 2253+2219 Dynamical Masses vs Virial_PondF Dinamical mases are lower than virial flux-weigthed mases in 66% of galaxies. Masas Estelares vs Viriales PondF Dynamical Masses vs Virial Colaps Diyamical masses are lower than Virial colapsed masses in 76% of galaxies. The Flux Weighted Virial Masses are lower than stelar mases in 53% of galaxies (24% in HII type and 29% in Disc type). IMF from Chabrier. Disk-Like HII-Like Flux-weighted virial masses are lower than stellar masses in el 36% of galaxies (19% in HII type and 17% in Disc type). IMF from Salpeter Disk-Like HII-Like Dynamical Masses vs Stellar M. Dinamical mases are lower than stellar masses in 82% of galaxies (66% in HII type and 86% in Disc type).