Measuring the Milky Way in M-dwarfs

Authors

  • Isabel van Vledder Leiden University
  • Dieuwertje van der Vlugt Leiden University

Abstract

We report 274 M-dwarfs found in the Brightest of Reionizing Galaxies (BoRG) survey for high redshift galaxies. Using these, we fitted a model for the disk and halo with a fixed scale length at h = 2.6 kpc. We found a scale height z0 of 0.60±0.03 kpc, flattening parameter κ of 0.45±0.04 and a powerlaw-index p of 2.4±0.07. For the total number of M-dwarfs in the disk and halo we found 26.7_(-6.2)^(+9.3)×10^9. The upper limit for the halo fraction of M-dwarfs in the halo is 7_(-4)^(+5) %. The total mass upper limit was determined to be 1.99_(-0.5)^(+0.73)×10^9 Solar masses.

References

LeBlanc F. 2010. An introduction to stellar astrophysics. Wiley, first edition.

Wilkins S. M., Stanway E. R., Bremer M. N. 2014. “High-redshift galaxies and low-mass stars.” MNRAS 439:1038-1050.

Scalo J. M. 1986. “The stellar initial mass function.” Fund. Cosmic Phys. 11:1-278.

Holwerda B. W. et al. 2014. “Milky Way Red Dwarfs in the BoRG Survey; Galactic Scale-height and the Distribution of Dwarf Stars in WFC3 Imaging.” ApJ 788:77.

Hawley S. L. et al. 2002. “Characterization of M, L, and T Dwarfs in the Sloan Digital Sky Survey.”AJ 123:3409-3427.

Bovy J., Rix H.-W., Liu C., Hogg D. W., Beers T. C., Lee Y. S. 2012b. “The Spatial Structure of Mono-abundance Sub-populations of the Milky Way Disk.” ApJ 753:148.

Cheng J. Y. et al. 2012. “A Short Scale Length for the α-enhanced Thick Disk of the Milky Way: Evidence from Low-latitude SEGUE Data.” ApJ 752:51.

Bensby T., Alves-Brito A., Oey M. S., Yong D., Meléndez J. 2011. “A First Constraint on the Thick Disk Scale Length: Differential Radial Abundances in K Giants at Galactocentric Radii 4, 8, and 12 kpc." ApJ 735:L46.

Reid I. N., Cruz K. L., Kirkpatrick J. D., Allen P. R., Mungall F., Liebert J., Lowrance P., Sweet A. 2008. “Meeting the Cool Neighbors. X. Ultracool Dwarfs from the 2MASS All-Sky Data Release.” AJ 136:1290-1311.

Jurić M. et al. 2008. “The Milky Way Tomography with SDSS. I. Stellar Number Density Distribution.”ApJ 673:864-914.

Foreman-Mackey D., Hogg D. W., Lang D., Goodman J. 2013. ”emcee: The MCMC Hammer.” PASP 125:306-312.

Weisz D. R. et al. 2013. “The Panchromatic Hubble Andromeda Treasury. IV. A Probabilistic Approach to Inferring the High-mass Stellar Initial Mass Function and Other Power-law Functions.” ApJ 762:123.

Brooks S., Gelman A., Jones G., Meng X.-L. 2011. Handbook of Markov Chain Monte Carlo. CRC press.

Cooper A. P., D'Souza R., Kauffmann G., Wang J., Boylan-Kolchin M., Guo Q., Frenk C. S., White S. D. M. 2013. “Galactic accretion and the outer structure of galaxies in the CDM model.” MNRAS 434:3348-3367.

Courteau S., Widrow L. M., McDonald M., Guhathakurta P., Gilbert K. M., Zhu Y., Beaton R. L., Majewski S. R. 2011. “The Luminosity Profile and Structural Parameters of the Andromeda Galaxy.” ApJ 739:2

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Published

2015-11-20

How to Cite

van Vledder, I., & van der Vlugt, D. (2015). Measuring the Milky Way in M-dwarfs. Student Undergraduate Research E-Journal!, 1. Retrieved from https://journals.open.tudelft.nl/sure/article/view/1083

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Section

Economics & Social Sciences