ACRONYM IV: Three New, Young, Low-mass Spectroscopic Binaries. (arXiv:2007.15799v1 [astro-ph.SR])
<a href="http://arxiv.org/find/astro-ph/1/au:+Flagg_L/0/1/0/all/0/1">Laura Flagg</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Shkolnik_E/0/1/0/all/0/1">Evgenya L. Shkolnik</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Weinberger_A/0/1/0/all/0/1">Alycia Weinberger</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bowler_B/0/1/0/all/0/1">Brendan P. Bowler</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Skiff_B/0/1/0/all/0/1">Brian Skiff</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kraus_A/0/1/0/all/0/1">Adam L. Kraus</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Liu_M/0/1/0/all/0/1">Michael C. Liu</a>
As part of our search for new low-mass members of nearby young moving groups
(YMG), we discovered three low-mass, spectroscopic binaries, two of which are
not kinematically associated with any known YMG. Using high-resolution optical
spectroscopy, we measure the component and systemic radial velocities of the
systems, as well as their lithium absorption and H$alpha$ emission, both
spectroscopic indicators of youth. One system (2MASS J02543316-5108313,
M2.0+M3.0) we confirm as a member of the 40 Myr old Tuc-Hor moving group, but
whose binarity was previously undetected. The second young binary (2MASS
J08355977-3042306, K5.5+M1.5) is not a kinematic match to any known YMG, but
each component exhibits lithium absorption and strong and wide H$alpha$
emission indicative of active accretion, setting an upper age limit of 15 Myr.
The third system (2MASS J10260210-4105537, M1.0+M3.0) has been hypothesized in
the literature to be a member of the 10 Myr old TW Hya Association (TWA), but
with our measured systemic velocity, shows the binary is in fact not part of
any known YMG. This last system also has lithium absorption in each component,
and has strong and variable H$alpha$ emission, setting an upper age limit of
15 Myr based on the lithium detection.
As part of our search for new low-mass members of nearby young moving groups
(YMG), we discovered three low-mass, spectroscopic binaries, two of which are
not kinematically associated with any known YMG. Using high-resolution optical
spectroscopy, we measure the component and systemic radial velocities of the
systems, as well as their lithium absorption and H$alpha$ emission, both
spectroscopic indicators of youth. One system (2MASS J02543316-5108313,
M2.0+M3.0) we confirm as a member of the 40 Myr old Tuc-Hor moving group, but
whose binarity was previously undetected. The second young binary (2MASS
J08355977-3042306, K5.5+M1.5) is not a kinematic match to any known YMG, but
each component exhibits lithium absorption and strong and wide H$alpha$
emission indicative of active accretion, setting an upper age limit of 15 Myr.
The third system (2MASS J10260210-4105537, M1.0+M3.0) has been hypothesized in
the literature to be a member of the 10 Myr old TW Hya Association (TWA), but
with our measured systemic velocity, shows the binary is in fact not part of
any known YMG. This last system also has lithium absorption in each component,
and has strong and variable H$alpha$ emission, setting an upper age limit of
15 Myr based on the lithium detection.
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