Abstract Details
| Name: Sushma Kurapati Affiliation: Research Scholar Conference ID: ASI2016_822 Title : Dark and visible matter in gas rich dwarf galaxies Authors and Co-Authors : Jayaram N Chengalur, National Centre for Radio Astrophysics - TIFR Abstract Type : Poster Abstract Category : Extragalactic astronomy Abstract : We present the Giant Meterwave Radio Telescope (GMRT) observations of two gas rich dwarf galaxies J0626+24 and KDG192 in the HI 21 cm line. J0626+24 is a void dwarf galaxy located in Lynx-Cancer void. The HI velocity fields for both the galaxies are regular and show systematic pattern that is consistent with the rotational motion. However, for both the galaxies, velocity fields show kinematical asymmetry between two halves of the galaxy. We derive the rotation curves using tilted ring model and fit mass models to them. Mass modelling of both the galaxies show that, they can be well fit with either a modified isothermal halo or a NFW halo. For both galaxies, in the case of NFW halo, the concentration parameter obtained using best fit differs significantly from the expected concentration parameter(from the scaling relations for LCDM models). We compiled a set of dwarf galaxies from the literature, compared their dark matter halo properties to the void dwarf galaxy(J0626+24). We find that parameters of dark matter halo of void galaxy don't deviate from the distribution of dwarf galaxies in high density regions. We also find that the rotation curves derived using Modified Newtonian Dynamics (MOND) also provide reasonable fit for both the galaxies. But the critical acceleration parameter obtained from the MOND fits, differs from the critical acceleration parameter expected from MOND theory. |