Discovery of the presence of young STARS in the leading arm of the magellanic stream and in the periphery of the large magellanic cloud (casetti-dinescu ET AL. 2014, moni bidin ET AL. 2017) poses a…

Discovery of the presence of young STARS in the leading arm of the magellanic stream and in the periphery of the large magellanic cloud (casetti-dinescu ET AL. 2014, moni bidin ET AL. 2017) poses a fundamental question as to how star formation can occur in intergalactic space within an environment of very low gas density. Recent models indicate that the hydrodynamical interaction with the gaseous component of the milky way may be of significant importance in shaping the leading arm of the magellanic stream; however models are still poorly constrained due to a lack of observational data. The existence of such STARS is crucial as IT informs on both star-formation and the clouds' interaction with one another and with the milky way. Moreover, STARS, as opposed to gas, provide secure distances to constrain the interactions. In the discovery of these young STARS, the galex UV mission played the key role in selecting potential candidates. Together with infrared photometry from 2MASS and optical v from ground-based data, our team developed a method to select such candidates that were then followed up with spectroscopy (casetti-dinescu ET AL. 2012). This pilot study demonstrated that, with large sky coverage, our team could explore significant portions of the magellanic stream, whereas previously only regions adjacent to the clouds had been studied. Still, the pilot study was limited to the southern sky (DEC. = -20 ). Here, we propose to recreate a young-star candidate list using two completed NASA space missions: the recently updated galex (DR6PLUS7) and the infrared wise missions. Together with optical photometry from gaia DR1 (and/or panstarrs), we will increase the sample of candidate OB-type STARS by exploring a volume of space over four times that of our previous, pilot study. The area coverage for the proposed new study will be the entire sky; previous spatial gaps in earlier versions of galex are now filled in, and the depth of the study will increase by 0.3 to 0.5 magnitudes due to use of allwise. By covering the entire sky, we will be able to explore the presence (or lack thereof) of such STARS diametrically opposite to the LA, where IT is inferred the magellanic stream is crossing the galactic plane a second time, if the clouds have had two pericenter passages about the galaxy. Alternatively, we may find entirely new structure at the edge of the galactic disk, related to interactions with other yetunknown milky-way satellites, or due to ejection mechanisms from OB associations in the disk. Star-forming regions as informed from OB-type STARS have been studied in our galaxy and in external galaxies, in well-known gas-rich regions. The novelty of our study is that IT is designed to find such STARS in unexpected regions by exploring the entire sky. IT is noted that within the time frame of this proposal, gaia data release 2 will become available; therefore, with these candidates having already been identified, we will be able to further investigate their distances and kinematics. Our list of candidates will be made publicly available for follow-up spectroscopic studies.