The Spitzer microlensing program as a probe for globular cluster planets : analysis of OGLE-2015-BLG-0448
Abstract
The microlensing event OGLE-2015-BLG-0448 was observed by Spitzer and lay within the tidal radius of the globular cluster NGC 6558. The event had moderate magnification and was intensively observed, hence it had the potential to probe the distribution of planets in globular clusters.We measure the proper motion of NGC 6558 μcl(N, E)=(+0.36 ± 0.10,+1.42 ± 0.10) mas yr-1) as well as the source and show that the lens is not a cluster member. Even though this particular event does not probe the distribution of planets in globular clusters, other potential cluster lens events can be verified using our methodology. Additionally, we find that microlens parallax measured using Optical Gravitational Lens Experiment (OGLE) photometry is consistent with the value found based on the light curve displacement between the Earth and Spitzer.
Citation
Poleski , R , Zhu , W , Christie , G W , Udalski , A , Gould , A , Bachelet , E , Skottfelt , J , Calchi Novati , S , Szymański , M K , Soszyński , I , Pietrzyński , G , Wyrzykowski , Ł , Ulaczyk , K , Pietrukowicz , P , Kozłowski , S , Skowron , J , Mróz , P , Pawlak , M , Beichman , C , Bryden , G , Carey , S , Fausnaugh , M , Gaudi , B S , Henderson , C B , Pogge , R W , Shvartzvald , Y , Wibking , B , Yee , J C , Beatty , T G , Eastman , J D , Drummond , J , Friedmann , M , Henderson , M , Johnson , J A , Kaspi , S , Maoz , D , McCormick , J , McCrady , N , Natusch , T , Ngan , H , Porritt , I , Relles , H M , Sliski , D H , Tan , T-G , Wittenmyer , R A , Wright , J T , Street , R A , Tsapras , Y , Bramich , D M , Horne , K , Snodgrass , C , Steele , I A , Menzies , J , Figuera Jaimes , R , Wambsganss , J , Schmidt , R , Cassan , A , Ranc , C , Mao , S , Bozza , V , Dominik , M , Hundertmark , M P G , Jørgensen , U G , Andersen , M I , Burgdorf , M J , Ciceri , S , D’Ago , G , Evans , D F , Gu , S-H , Hinse , T C , Kains , N , Kerins , E , Korhonen , H , Kuffmeier , M , Mancini , L , Popovas , A , Rabus , M , Rahvar , S , Rasmussen , R T , Scarpetta , G , Southworth , J , Surdej , J , Unda-Sanzana , E , Verma , P , von Essen , C , Wang , Y-B & Wertz , O 2016 , ' The Spitzer microlensing program as a probe for globular cluster planets : analysis of OGLE-2015-BLG-0448 ' Astrophysical Journal , vol 823 , no. 1 , 63 . DOI: 10.3847/0004-637X/823/1/63
Publication
Astrophysical Journal
Status
Peer reviewed
ISSN
0004-637XType
Journal article
Rights
© 2016, The American Astronomical Society. This work is made available online in accordance with the publisher’s policies. This is the final published version of the work, which was originally published at iopscience.iop.org / https://dx.doi.org/10.3847/0004-637X/823/1/63
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