Milky Way L/T/M-dwarfs identified in BoRG survey

Using spectroscopically identified M-dwarfs in two public surveys, the Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey and the Early Release Science mosaics, we identify a morphological selection criterion using the half-light radius (r_50_), a near-infrared J-H, G-J color region where M-dwarfs are found, and a V-J relation with M-dwarf subtype.

We apply this morphological selection of stellar objects, color-color selection of M-dwarfs, and optical-near-infrared color subtyping to compile a catalog of 274 M-dwarfs belonging to the disk of the Milky Way with a limiting magnitude of m_F125W_<24(AB). Based on the M-dwarf statistics, we conclude that (1) the previously identified north-south discrepancy in M-dwarf numbers persists in our sample; there are more M-dwarfs in the northern fields on average than in southern ones, (2) the Milky Way's single disk scale-height for M-dwarfs is 0.3-4 kpc, depending on subtype, (3) the scale-height depends on M-dwarf subtype with early types (M0-4) high scale-height (z_0_=3-4 kpc) and later types M5 and above in the thin disk (z_0_=0.3-0.5 kpc), (4) a second component is visible in the vertical distribution, with a different, much higher scale-height in the southern fields compared to the northern ones.