J/ApJ/814/92 Spitzer IRAC events observed in crowded fields (Calchi+, 2015) ================================================================================ Spitzer IRAC photometry for time series in crowded fields. Calchi Novati S., Gould A., Yee J.C., Beichman C., Bryden G., Carey S., Fausnaugh M., Gaudi B.S., Henderson C.B., Pogge R.W., Shvartzvald Y., Wibking B., Zhu W., (the Spitzer team), Udalski A., Poleski R., Pawlak M., Szymanski M.K., Skowron J., Mroz P., Kozlowski S., Wyrzykowski L., Pietrukowicz P., Pietrzynski G., Soszynski I., Ulaczyk K., (the Ogle group) =2015ApJ...814...92C (SIMBAD/NED BibCode) ================================================================================ ADC_Keywords: Gravitational lensing ; Ephemerides Keywords: gravitational lensing: micro - techniques: photometric Abstract: We develop a new photometry algorithm that is optimized for the Infrared Array Camera (IRAC) Spitzer time series in crowded fields and that is particularly adapted to faint or heavily blended targets. We apply this to the 170 targets from the 2015 Spitzer microlensing campaign and present the results of three variants of this algorithm in an online catalog. We present detailed accounts of the application of this algorithm to two difficult cases, one very faint and the other very crowded. Several of Spitzer's instrumental characteristics that drive the specific features of this algorithm are shared by Kepler and WFIRST, implying that these features may prove to be a useful starting point for algorithms designed for microlensing campaigns by these other missions. Description: In Table 1 we list the 170 events monitored in 2015. For each, we report the event name, the coordinates, the first and last day of observation, and the number of observed epochs. The events were chosen based on the microlensing alerts provided by the OGLE (Udalski et al. 2015AcA....65....1U) and MOA (Bond et al. 2004ApJ...606L.155B) collaborations. The current analysis is based on the preliminary reduced data made available by the Spitzer Science Center almost in real time (on average, 2-3 days after the observations). The final reduction of the data is now publicly available at the NASA/IPAC Infrared Science Database (IRSA, http://irsa.ipac.caltech.edu/frontpage/). File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file table1.dat 61 170 Observed Events -------------------------------------------------------------------------------- See also: II/213 : OGLE Galactic Bulge periodic variables (Udalski+ 1996) J/AcA/50/1 : OGLE microlensing events in Galactic Bulge (Udalski+, 2000) J/ApJ/636/240 : OGLE II microlensing parameters (Sumi+, 2006) J/ApJ/778/150 : Microlensing events toward the Bulge from MOA-II (Sumi+, 2013) Byte-by-byte Description of file: table1.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 18 A18 --- Event Event name (1) 19 A1 --- n_Event [a] Note on Event (2) 21- 30 F10.6 deg RAdeg Right Ascension in decimal degrees (J2000) 32- 41 F10.6 deg DEdeg Declination in decimal degrees (J2000) 43- 49 F7.2 d HJD1 Heliocentric Julian Date of first Spitzer observation (HJD-2450000) 51- 57 F7.2 d HJD2 Heliocentric Julian Date of last Spitzer observation (HJD-2450000) 59- 61 I3 --- Epochs [7/211] Number of observed epochs -------------------------------------------------------------------------------- Note (1): We note that two out of the 10 MOA events have also been observed by the OGLE collaboration (specifically, MOA-BLG-2015-020 and MOA-BLG-2015-245 are also known as OGLE-BLG-2015-0102 and OGLE-BLG-2015-1286, respectively), and 64 out of the 160 OGLE events have also been observed by the MOA collaboration (for the details on this we refer to the MOA microlensing alert web page http://www.phys.canterbury.ac.nz/moa/microlensing_alerts.html). Note (2): Note as follows: a = This event is also known as OGLE-BLG-2015-1253. -------------------------------------------------------------------------------- History: From electronic version of the journal ================================================================================ (End) Prepared by Tiphaine Pouvreau [CDS] 16-Oct-2017