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Empirical Study Of Simulated Two-Planet Microlensing Events, Wei Zhu, Andrew Gould, Matthew Penny, Shude Mao, Rieul Gendron
Empirical Study Of Simulated Two-Planet Microlensing Events, Wei Zhu, Andrew Gould, Matthew Penny, Shude Mao, Rieul Gendron
Faculty Publications
We undertake the first study of two-planet microlensing models recovered from simulations of microlensing events generated by realistic multiplanet systems in which 292 planetary events, including 16 two-planet events, were detected from 6690 simulated light curves. We find that when two planets are recovered, their parameters are usually close to those of the two planets in the system most responsible for the perturbations. However, in 1 of the 16 examples, the apparent mass of both detected planets was more than doubled by the unmodeled influence of a third, massive planet. This fraction is larger than but statistically consistent with the …
Variability Of Optical Counterparts In The Chandra Galactic Bulge Survey, C. T. Britt, R. I. Hynes, C. B. Johnson, A. Baldwin, P. G. Jonker, G. Nelemans, M. A.P. Torres, T. Maccarone, D. Steeghs, S. Greiss, C. Heinke, C. G. Bassa, A. Collazzi, A. Villar, M. Gabb, L. Gossen
Variability Of Optical Counterparts In The Chandra Galactic Bulge Survey, C. T. Britt, R. I. Hynes, C. B. Johnson, A. Baldwin, P. G. Jonker, G. Nelemans, M. A.P. Torres, T. Maccarone, D. Steeghs, S. Greiss, C. Heinke, C. G. Bassa, A. Collazzi, A. Villar, M. Gabb, L. Gossen
Faculty Publications
We present optical light curves of variable stars consistent with the positions of X-ray sources identified with the Chandra X-ray Observatory for the Chandra Galactic Bulge Survey (GBS). Using data from the Mosaic-II instrument on the Blanco 4 m Telescope at CTIO, we gathered time-resolved photometric data on timescales from ∼2 hr to 8 days over the 3/4 of the X-ray survey containing sources from the initial GBS catalog. Among the light curve morphologies we identify are flickering in interacting binaries, eclipsing sources, dwarf nova outbursts, ellipsoidal variations, long period variables, spotted stars, and flare stars. Eighty-seven percent of X-ray …
Predictions For Microlensing Planetary Events From Core Accretion Theory, Wei Zhu, Matthew Penny, Shude Mao, Andrew Gould, Rieul Gendron
Predictions For Microlensing Planetary Events From Core Accretion Theory, Wei Zhu, Matthew Penny, Shude Mao, Andrew Gould, Rieul Gendron
Faculty Publications
We conduct the first microlensing simulation in the context of a planet formation model. The planet population is taken from the Ida & Lin core accretion model for 0.3 M stars. With 6690 microlensing events, we find that for a simplified Korea Microlensing Telescopes Network (KMTNet), the fraction of planetary events is 2.9%, out of which 5.5% show multiple-planet signatures. The numbers of super-Earths, super-Neptunes, and super-Jupiters detected are expected to be almost equal. Our simulation shows that high-magnification events and massive planets are favored by planet detections, which is consistent with previous expectation. However, we notice that extremely high-magnification …
Near-Infrared Counterparts To The Galactic Bulge Survey X-Ray Source Population, S. Greiss, D. Steeghs, P. G. Jonker, M. A.P. Torres, T. J. Maccarone, R. I. Hynes, C. T. Britt, G. Nelemans, B. T. Gänsicke
Near-Infrared Counterparts To The Galactic Bulge Survey X-Ray Source Population, S. Greiss, D. Steeghs, P. G. Jonker, M. A.P. Torres, T. J. Maccarone, R. I. Hynes, C. T. Britt, G. Nelemans, B. T. Gänsicke
Faculty Publications
We report on the near-infrared matches, drawn from three surveys, to the 1640 unique X-ray sources detected by Chandra in the Galactic Bulge Survey (GBS). This survey targets faint X-ray sources in the bulge, with a particular focus on accreting compact objects. We present all viable counterpart candidates and associate a false alarm probability (FAP) to each near-infrared match in order to identify the most likely counterparts. The FAP takes into account a statistical study involving a chance alignment test, as well as considering the positional accuracy of the individual X-ray sources. We find that although the star density in …
Symbiotic Stars In Ogle Data - I. Large Magellanic Cloud Systems, R. Angeloni, C. E. Ferreira Lopes, N. Masetti, F. Di Mille, P. Pietrukowicz, A. Udalski, B. E. Schaefer, P. Parisi, R. Landi, C. Navarrete, M. Catelan, T. H. Puzia, D. Guzman
Symbiotic Stars In Ogle Data - I. Large Magellanic Cloud Systems, R. Angeloni, C. E. Ferreira Lopes, N. Masetti, F. Di Mille, P. Pietrukowicz, A. Udalski, B. E. Schaefer, P. Parisi, R. Landi, C. Navarrete, M. Catelan, T. H. Puzia, D. Guzman
Faculty Publications
Symbiotic stars are long-orbital-period interacting binaries characterized by extended emission over the whole electromagnetic range and by complex photometric and spectroscopic variability. In this paper, the first of a series, we present Optical Gravitational Lensing Experiment (OGLE) light curves of all the confirmed symbiotic stars in the Large Magellanic Cloud, with one exception. By careful visual inspection and combined time series analysis techniques, we investigate for the first time in a systematic way the photometric properties of these astrophysical objects, trying in particular to distinguish the nature of the cool component (e.g. semiregular Variable versus OGLE small-amplitude red giant), to …
Cxogbs J173620.2-293338: A Candidate Symbiotic X-Ray Binary Associated With A Bulge Carbon Star, Robert I. Hynes, M. A.P. Torres, C. O. Heinke, T. J. Maccarone, V. J. Mikles, C. T. Britt, C. Knigge, S. Greiss, P. G. Jonker, D. Steeghs, G. Nelemans, R. M. Bandyopadhyay, C. B. Johnson
Cxogbs J173620.2-293338: A Candidate Symbiotic X-Ray Binary Associated With A Bulge Carbon Star, Robert I. Hynes, M. A.P. Torres, C. O. Heinke, T. J. Maccarone, V. J. Mikles, C. T. Britt, C. Knigge, S. Greiss, P. G. Jonker, D. Steeghs, G. Nelemans, R. M. Bandyopadhyay, C. B. Johnson
Faculty Publications
The Galactic Bulge Survey (GBS) is a wide but shallow X-ray survey of regions above and below the Plane in the Galactic Bulge. It was performed using the Chandra X-ray Observatory's ACIS camera. The survey is primarily designed to find and classify low luminosity X-ray binaries. The combination of the X-ray depth of the survey and the accessibility of optical and infrared counterparts makes this survey ideally suited to identification of new symbiotic X-ray binaries (SyXBs) in the Bulge. We consider the specific case of the X-ray source CXOGBS J173620.2-293338. It is coincident to within 1 arcsec with a very …
Planet Hunters. Vi. An Independent Characterization Of Koi-351 And Several Long Period Planet Candidates From The Kepler Archival Data, Joseph R. Schmitt, Ji Wang, Debra A. Fischer, Kian J. Jek, John C. Moriarty, Tabetha S. Boyajian, Megan E. Schwamb, Chris Lintott, Stuart Lynn, Arfon M. Smith, Michael Parrish, Kevin Schawinski, Robert Simpson, Daryll Lacourse, Mark R. Omohundro, Troy Winarski, Samuel Jon Goodman, Tony Jebson, Hans Martin Schwengeler, David A. Paterson, Johann Sejpka, Ivan Terentev, Tom Jacobs, Nawar Alsaadi, Robert C. Bailey, Tony Ginman, Pete Granado, Kristoffer Vonstad Guttormsen, Franco Mallia, Alfred L. Papillon, Franco Rossi, Miguel Socolovsky
Planet Hunters. Vi. An Independent Characterization Of Koi-351 And Several Long Period Planet Candidates From The Kepler Archival Data, Joseph R. Schmitt, Ji Wang, Debra A. Fischer, Kian J. Jek, John C. Moriarty, Tabetha S. Boyajian, Megan E. Schwamb, Chris Lintott, Stuart Lynn, Arfon M. Smith, Michael Parrish, Kevin Schawinski, Robert Simpson, Daryll Lacourse, Mark R. Omohundro, Troy Winarski, Samuel Jon Goodman, Tony Jebson, Hans Martin Schwengeler, David A. Paterson, Johann Sejpka, Ivan Terentev, Tom Jacobs, Nawar Alsaadi, Robert C. Bailey, Tony Ginman, Pete Granado, Kristoffer Vonstad Guttormsen, Franco Mallia, Alfred L. Papillon, Franco Rossi, Miguel Socolovsky
Faculty Publications
We report the discovery of 14 new transiting planet candidates in the Kepler field from the Planet Hunters citizen science program. None of these candidates overlapped with Kepler Objects of Interest (KOIs) at the time of submission. We report the discovery of one more addition to the six planet candidate system around KOI-351, making it the only seven planet candidate system from Kepler. Additionally, KOI-351 bears some resemblance to our own solar system, with the inner five planets ranging from Earth to mini-Neptune radii and the outer planets being gas giants; however, this system is very compact, with all seven …
First Searches For Optical Counterparts To Gravitational-Wave Candidate Events, M. Constancio, J. Aasi, J. Abadie, B. P. Abbott, R. Abbott, T. Abbott, M. R. Abernathy, T. Accadia, F. Acernese, C. Adams, T. Adams, R. X. Adhikari, C. Affeldt, M. Agathos, N. Aggarwal, O. D. Aguiar, P. Ajith, B. Allen, A. Allocca, E. Amador Ceron, D. Amariutei, R. A. Anderson, S. B. Anderson, W. G. Anderson, K. Arai, M. C. Araya, C. Arceneaux, J. Areeda, S. Ast, S. M. Aston, P. Astone, P. Aufmuth, C. Aulbert
First Searches For Optical Counterparts To Gravitational-Wave Candidate Events, M. Constancio, J. Aasi, J. Abadie, B. P. Abbott, R. Abbott, T. Abbott, M. R. Abernathy, T. Accadia, F. Acernese, C. Adams, T. Adams, R. X. Adhikari, C. Affeldt, M. Agathos, N. Aggarwal, O. D. Aguiar, P. Ajith, B. Allen, A. Allocca, E. Amador Ceron, D. Amariutei, R. A. Anderson, S. B. Anderson, W. G. Anderson, K. Arai, M. C. Araya, C. Arceneaux, J. Areeda, S. Ast, S. M. Aston, P. Astone, P. Aufmuth, C. Aulbert
Faculty Publications
During the Laser Interferometer Gravitational-wave Observatory and Virgo joint science runs in 2009-2010, gravitational wave (GW) data from three interferometer detectors were analyzed within minutes to select GW candidate events and infer their apparent sky positions. Target coordinates were transmitted to several telescopes for follow-up observations aimed at the detection of an associated optical transient. Images were obtained for eight such GW candidates. We present the methods used to analyze the image data as well as the transient search results. No optical transient was identified with a convincing association with any of these candidates, and none of the GW triggers …