Gravitational Microlensing Events from the First Year of the Northern Galactic Plane Survey by the Zwicky Transient Facility

Mróz, P.; Street, R. A.; Bachelet, E.; Ofek, E. O.; Bellm, Eric C.; Dekany, Richard; Duev, Dmitry A.; Gal‐Yam, A.; Graham, M. J.; Masci, Frank J.; Porter, Michael; Rusholme, B.; Smith, Roger M.; Soumagnac, Maayane T.; Zolkower, Jeffry

doi:10.3847/2515-5172/ab7021

Cited by 15 publications

(20 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We crosscorrelated our lists of microlensing events with objects reported in the Transient Name Server, 5 finding that 23 of them were previously reported as possible astrophysical transients by the Gaia Science Alerts program 6 (Hodgkin et al 2013). The All-Sky Automated Survey for SuperNovae detected four events (Shappee et al 2014) and two were found by Mróz et al (2020) in the photometric data from ZTF.…”

Section: Selection Of Microlensing Eventsmentioning

confidence: 96%

“…About 200 microlensing event candidates were discovered as part of Gaia Science Alerts (Hodgkin et al 2013;Wyrzykowski 2016;Kruszyńska & Wyrzykowski 2018; Ł. Wyrzykowski 2020, private communication) including a spectacular binary event, Gaia16aye (Wyrzykowski et al 2020;l=65°). Recently, Mróz et al (2020) presented the discovery of 30 microlensing events detected in the first year of northern Galactic plane survey by the Zwicky Transient Facility (ZTF; Bellm et al 2019;Graham et al 2019).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Microlensing Optical Depth and Event Rate in the OGLE-IV Galactic Plane Fields

Mróz

Udalski

Szymański

et al. 2020

ApJS

Self Cite

View full text Add to dashboard Cite

Searches for gravitational microlensing events are traditionally concentrated on the central regions of the Galactic bulge but many microlensing events are expected to occur in the Galactic plane, far from the Galactic Center. Owing to the difficulty in conducting high-cadence observations of the Galactic plane over its vast area, which are necessary for the detection of microlensing events, their global properties were hitherto unknown. Here, we present results of the first comprehensive search for microlensing events in the Galactic plane. We searched an area of almost 3000 square degrees along the Galactic plane (<  b 7 | | , 0°<l<50°, 190°<l<360°) observed by the Optical Gravitational Lensing Experiment (OGLE) during 2013-2019 and detected 630 events. We demonstrate that the mean Einstein timescales of Galactic plane microlensing events are on average three times longer than those of Galactic bulge events, with little dependence on the Galactic longitude. We also measure the microlensing optical depth and event rate as a function of Galactic longitude and demonstrate that they exponentially decrease with the angular distance from the Galactic Center (with the characteristic angular scale length of 32°). The average optical depth decreases from 0.5×10 −6 at l=10°to 1.5×10 −8 in the Galactic anticenter. We also find that the optical depth in the longitude range 240°<l<330°is asymmetric about the Galactic equator, which we interpret as a signature of the Galactic warp.

show abstract

Section: Selection Of Microlensing Eventsmentioning

confidence: 96%

Section: Introductionmentioning

confidence: 99%

Microlensing Optical Depth and Event Rate in the OGLE-IV Galactic Plane Fields

Mróz

Udalski

Szymański

et al. 2020

ApJS

Self Cite

View full text Add to dashboard Cite

show abstract

“…We also tested this module using the ZTF public alert stream, since some microlensing events have already been found during the first years (Mróz et al 2020). We analysed the alert data taken between November 2019 and June 2020.…”

Section: Microlensing Eventsmentioning

confidence: 99%

fink, a new generation of broker for the LSST community

Möller

Peloton

Ishida

et al. 2020

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

Fink is a broker designed to enable science with large time-domain alert streams such as the one from the upcoming Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST). It exhibits traditional astronomy broker features such as automatised ingestion, annotation, selection and redistribution of promising alerts for transient science. It is also designed to go beyond traditional broker features by providing real-time transient classification which is continuously improved by using state-of-the-art Deep Learning and Adaptive Learning techniques. These evolving added values will enable more accurate scientific output from LSST photometric data for diverse science cases while also leading to a higher incidence of new discoveries which shall accompany the evolution of the survey. In this paper we introduce Fink, its science motivation, architecture and current status including first science verification cases using the Zwicky Transient Facility alert stream.

show abstract

“…Vanderbosch et al (2020) discovered a white dwarf with exocomets, the second of such a system. ZTF has also been used to discover a large number of outbursting or flaring objects: CVs and microlensing events (Szkody et al 2020;Mróz et al 2020).…”

Section: Introductionmentioning

confidence: 99%

The ZTF Source Classification Project. I. Methods and Infrastructure

Roestel

Duev

Mahabal

et al. 2021

Self Cite

View full text Add to dashboard Cite

The Zwicky Transient Facility (ZTF) has been observing the entire northern sky since the start of 2018 down to a magnitude of 20.5 (5σ for 30 s exposure) in the g, r, and i filters. Over the course of two years, ZTF has obtained light curves of more than a billion sources, each with 50-1000 epochs per light curve in g and r, and fewer in i. To be able to use the information contained in the light curves of variable sources for new scientific discoveries, an efficient and flexible framework is needed to classify them. In this paper, we introduce the methods and infrastructure that will be used to classify all ZTF light curves. Our approach aims to be flexible and modular and allows the use of a dynamical classification scheme and labels, continuously evolving training sets, and the use of different machine-learning classifier types and architectures. With this setup, we are able to continuously update and improve the classification of ZTF light curves as new data become available, training samples are updated, and new classes need to be incorporated.

show abstract

Gravitational Microlensing Events from the First Year of the Northern Galactic Plane Survey by the Zwicky Transient Facility

Cited by 15 publications

References 12 publications

Microlensing Optical Depth and Event Rate in the OGLE-IV Galactic Plane Fields

Microlensing Optical Depth and Event Rate in the OGLE-IV Galactic Plane Fields

fink, a new generation of broker for the LSST community

The ZTF Source Classification Project. I. Methods and Infrastructure

Contact Info

Product

Resources

About