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J/MNRAS/457/4089    Frequency of snowline-region planets    (Shvartzvald+, 2016)

The frequency of snowline-region planets from four years of OGLE-MOA-Wise second-generation microlensing. Shvartzvald Y., Maoz D., Udalski A., Sumi T., Friedmann M., Kaspi S., Poleski R., Szymanski M.K., Skowron J., Kozlowski S., Wyrzykowski L., Mroz P., Pietrukowicz P., Pietrzynski G., Soszynski I., Ulaczyk K., Abe F., Barry R.K., Bennett D.P., Bhattacharya A., Bond I.A., Freeman M., Inayama K., Itow Y., Koshimoto N., Ling C.H., Masuda K., Fukui A., Matsubara Y., Muraki Y., Ohnishi K., Rattenbury N.J., Saito T., Sullivan D.J., Suzuki D., Tristram P.J., Wakiyama Y., Yonehara A. <Mon. Not. R. Astron. Soc., 457, 4089-4113 (2016)> =2016MNRAS.457.4089S (SIMBAD/NED BibCode)
ADC_Keywords: Surveys ; Gravitational lensing ; Stars, double and multiple ; Planets Keywords: gravitational lensing: micro - surveys - binaries: general - planetary systems - Galaxy: stellar content Abstract: We present a statistical analysis of the first four seasons from a 'second-generation' microlensing survey for extrasolar planets, consisting of near-continuous time coverage of 8 deg2 of the Galactic bulge by the Optical Gravitational Lens Experiment (OGLE), Microlensing Observations in Astrophysics (MOA), and Wise microlensing surveys. During this period, 224 microlensing events were observed by all three groups. Over 12 per cent of the events showed a deviation from single-lens microlensing, and for ∼one-third of those the anomaly is likely caused by a planetary companion. For each of the 224 events, we have performed numerical ray-tracing simulations to calculate the detection efficiency of possible companions as a function of companion-to-host mass ratio and separation. Accounting for the detection efficiency, we find that 55+34-22 per cent of microlensed stars host a snowline planet. Moreover, we find that Neptune-mass planets are ∼10 times more common than Jupiter-mass planets. The companion-to-host mass-ratio distribution shows a deficit at q∼10-2, separating the distribution into two companion populations, analogous to the stellar-companion and planet populations, seen in radial-velocity surveys around solar-like stars. Our survey, however, which probes mainly lower mass stars, suggests a minimum in the distribution in the super-Jupiter mass range, and a relatively high occurrence of brown-dwarf companions. Description: Our genII survey network is a collaboration between three groups: OGLE, MOA, and Wise. The OGLE and MOA groups regularly monitor a large region of the Galactic bulge, and routinely identify and monitor microlensing events. The Wise group monitors a field of 8 deg2, within the observational footprints of both OGLE and MOA, having the highest event rates based on previous years' observations (see Shvartzvald & Maoz, 2012MNRAS.419.3631S). The sample of microlensing events analysed here consists of 224 events from the 2011-2014 bulge seasons, observed by all three groups, and with each group having data near the peak of the event. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file tablea1.dat 133 230 Event summary
See also: J/AcA/50/1 : OGLE microlensing events in Galactic Bulge (Udalski+, 2000) J/AcA/51/175 : OGLE-II DIA microlensing events (Wozniak+, 2001) J/ApJ/636/240 : OGLE II microlensing parameters (Sumi+, 2006) J/ApJ/711/L48 : 2008 OGLE Bulge microlensing alerts (Cohen+, 2010) J/ApJS/216/12 : OGLE-III Galactic bulge microlensing events (Wyrzykowski+ 2015) J/ApJ/778/150 : MOA-II microlensing events toward the Bulge (Sumi+, 2013) J/ApJ/827/139 : MOA-II microlensing optical depth + event rates (Sumi+, 2016) Byte-by-byte Description of file: tablea1.dat
Bytes Format Units Label Explanations
1- 3 A3 --- Seq Sequential number (1-224) + 6 (X1-X6) anomalous events 5- 11 A7 --- OGLE OGLE number (NN-NNNN, EWS 20NN-BLG-NNNN) 13- 18 A6 --- MOA MOA number (NN-NNN, MOA 20NN-BLG-NNN) 20- 25 F6.3 --- mu0 Minimum impact parameter 27- 34 F8.3 d t0 Time of the closest lens-source approach (HJD-2450000) 36- 42 F7.3 d tE Einstein radius crossing time (the events time-scale) 44- 51 F8.3 10-3 rho ?=0 Angular Einstein radius (rho=theta*/thetaE) 52 A1 --- n_rho [*] Note on rho (1) 53- 58 F6.3 --- piEE East component of the orbital microlens parallax vector piE 59 A1 --- n_piEE [*] Note on piEE (1) 60- 65 F6.3 --- piEN North component of the orbital microlens parallax vector piE 66 A1 --- n_piEN [*] Note on piEN (1) 67- 72 F6.3 mag Ibl Baseline magnitude 74- 78 F5.3 --- fbl Baseline flux 80- 85 F6.3 --- e_mu0 rms uncertainty on mu0 86- 91 F6.3 d e_t0 rms uncertainty on t0 93- 99 F7.3 d e_tE rms uncertainty on tE 101-109 F9.3 10-3 e_rho rms uncertainty on rho 111-115 F5.3 --- e_piEE rms uncertainty on piEE 117-121 F5.3 --- e_piEN rms uncertainty on piEN 123-127 F5.3 mag e_Ibl rms uncertainty on fbl 129-133 F5.3 --- e_fbl rms uncertainty on fbl
Note (1): * indicates significant detections of finite source effects and parallax.
History: From electronic version of the journal
(End) Patricia Vannier [CDS] 01-Jun-2017
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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