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Date and Time of the Query: 2019-04-18 T03:53:35 PDT
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For refcode 2005ApJ...633..844P:
Retrieve 81 NED objects in this reference.
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Copyright by American Astronomical Society. Reproduced by permission
2005ApJ...633..844P Dark Matter and Stellar Mass in the Luminous Regions of Disk Galaxies James Pizagno, Francisco Prada, David H. Weinberg, Hans-Walter Rix, Daniel Harbeck, Eva K. Grebel, Eric F. Bell, Jon Brinkmann, Jon Holtzman, and Andrew West Abstract. We investigate the correlations among stellar mass (M_*_), disk scale length (R_d_), and rotation velocity at 2.2 disk scale lengths (V_2.2_) for a sample of 81 disk-dominated galaxies (disk/total >= 0.9) selected from the SDSS. We measure V_2.2_ from long-slit H{alpha} rotation curves and infer M_*_ from galaxy i-band luminosities (L_i_) and g-r colors. We find logarithmic slopes of 2.60+/-0.13 and 3.05+/-0.12 for the (forward fit) L_i_-V_2.2_ and M_*_-V_2.2_ relations, somewhat shallower than most previous studies, with intrinsic scatter of 0.13 and 0.16 dex, respectively. Our direct estimates of the total-to-stellar mass ratio within 2.2R_d_, assuming a Kroupa IMF, yield a median ratio of 2.4 for M_*_>10^10^ M_sun_ and 4.4 for M_*_=10^9^ -- 10^10^ M_sun_, with large scatter at a given M_*_ and R_d_. The typical ratio of the rotation speed predicted for the stellar disk alone to the observed rotation speed at 2.2R_d_ is ~0.65. The distribution of scale lengths at fixed M_*_ is broad, but we find no correlation between disk size and the residual from the M_*_-V_2.2_ relation, implying that the M_*_-V_2.2_ relation is an approximately edge-on view of the disk galaxy fundamental plane. Independent of the assumed IMF, this result implies that stellar disks do not, on average, dominate the mass within 2.2R_d_. We discuss our results in the context of infall models where disks form in adiabatically contracted cold dark matter halos. A model with a disk-to-halo mass ratio m_d_=0.05 provides a reasonable match to the R_d_-M_*_ distribution for spin parameters {lambda} ranging from ~0.04 to 0.08, and it yields a reasonable match to the mean M_*_-V_2.2_ relation. A model with m_d_=0.1 predicts overly strong correlations between disk size and M_*_-V_2.2_ residual. Explaining the wide range of halo-to-disk mass ratios within 2.2R_d_ requires significant scatter in m_d_ values, with systematically lower m_d_ for galaxies with lower M_*_ or lower stellar surface density {SIGMA}_*_. Key words: Cosmology: Dark Matter, Galaxies: Kinematics and Dynamics, Galaxies: Photometry
Retrieve 81 NED objects in this reference.
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