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تسجيل مستخدم جديدGalaxy And Mass Assembly (GAMA): The galaxy stellar mass function to $z=0.1$ from the r-band selected equatorial regions
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We derive the low redshift galaxy stellar mass function (GSMF), inclusive of dust corrections, for the equatorial Galaxy And Mass Assembly (GAMA) dataset covering 180 deg$^2$. We construct the mass function using a density-corrected maximum volume method, using masses corrected for the impact of optically thick and thin dust. We explore the galactic bivariate brightness plane ($M_star-mu$), demonstrating that surface brightness effects do not systematically bias our mass function measurement above 10$^{7.5}$ M$_{odot}$. The galaxy distribution in the $M-mu$-plane appears well bounded, indicating that no substantial population of massive but diffuse or highly compact galaxies are systematically missed due to the GAMA selection criteria. The GSMF is {fit with} a double Schechter function, with $mathcal M^star=10^{10.78pm0.01pm0.20}M_odot$, $phi^star_1=(2.93pm0.40)times10^{-3}h_{70}^3$Mpc$^{-3}$, $alpha_1=-0.62pm0.03pm0.15$, $phi^star_2=(0.63pm0.10)times10^{-3}h_{70}^3$Mpc$^{-3}$, and $alpha_2=-1.50pm0.01pm0.15$. We find the equivalent faint end slope as previously estimated using the GAMA-I sample, although we find a higher value of $mathcal M^star$. Using the full GAMA-II sample, we are able to fit the mass function to masses as low as $10^{7.5}$ $M_odot$, and assess limits to $10^{6.5}$ $M_odot$. Combining GAMA-II with data from G10-COSMOS we are able to comment qualitatively on the shape of the GSMF down to masses as low as $10^{6}$ $M_odot$. Beyond the well known upturn seen in the GSMF at $10^{9.5}$ the distribution appears to maintain a single power-law slope from $10^9$ to $10^{6.5}$. We calculate the stellar mass density parameter given our best-estimate GSMF, finding $Omega_star= 1.66^{+0.24}_{-0.23}pm0.97 h^{-1}_{70} times 10^{-3}$, inclusive of random and systematic uncertainties.
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