Search

We use the extended and updated Optical Gravitational Lensing Experiment (OGLE) Collection of Variable Stars to thoroughly analyze the distribution of RR Lyrae stars in the Magellanic Bridge. We use photometric metallicities to derive the absolute Wesenheit magnitude and individual distance of each RR Lyrae star. We confirm results from our earlier study showing that RR Lyrae stars are present in between the Magellanic Clouds, though their three-dimensional distribution more resembles two extended overlapping structures than a strict bridge-like connection. The contours do connect in the southern parts of the Bridge, albeit on a level too low to state that an evident connection exists. To test the sample numerically, we use multi-Gaussian fitting and conclude that there is no additional population or overdensity located in the Bridge. We also try to reproduce results on the putative RR Lyrae Magellanic Bridge stream by selecting RR Lyrae candidates from Gaia Data Release 1. We show that we are not able to obtain the evident connection of the Clouds without many spurious sources in the sample, as the cuts are not able to remove artifacts without eliminating the evident connection at the same time. Moreover, for the first time, we present the Gaia Data Release 2 RR Lyrae stars in the Magellanic Bridge area and show that their distribution matches our results. [ABSTRACT FROM AUTHOR]

We present a detailed analysis of the Magellanic Bridge Cepheid sample constructed using the Optical Gravitational Lensing Experiment Collection of Variable Stars. Our updated Bridge sample contains 10 classical and 13 anomalous Cepheids. We calculate their individual distances using optical period–Wesenheit relations and construct three-dimensional maps. Classical Cepheid (CC) on-sky locations match very well neutral hydrogen and young stars distributions; thus, they add to the overall young Bridge population. In three dimensions, 8 out of 10 CCs form a bridge-like connection between the Magellanic Clouds. The other two are located slightly farther away and may constitute the Counter Bridge. We estimate ages of our Cepheids to be less than 300 Myr for from 5 up to 8 out of 10, depending on whether the rotation is included. This is in agreement with a scenario where these stars were formed in situ after the last encounter of the Magellanic Clouds. Cepheids’ proper motions reveal that they are moving away from both Large and Small Magellanic Clouds. Anomalous Cepheids are more spread than CCs in both two and three dimensions, even though they form a rather smooth connection between the Magellanic Clouds. However, this connection does not seem to be bridge-like, as there are many outliers around both Magellanic Clouds. [ABSTRACT FROM AUTHOR]