Microlensing mass measurement from images of rotating gravitational arcs

Cassan, A.; Ranc, Clément; Absil, Olivier; Wyrzykowski, Ł.; Rybicki, K.; Bachelet, E.; Bouquin, Jean-Baptiste Le; Hundertmark, M.; Street, R. A.; Surdej, Jean; Tsapras, Y.; Wambsganß, J.; Wertz, O.

doi:10.1038/s41550-021-01514-w

Cited by 18 publications

(16 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, in the case of an individual event, the complete solution of the event, that is, computation of the lens mass and its distance, can only be achieved if the angular Einstein radius θ E is measured indirectly; for example through a finite source effect in single (Zub et al 2011;Yoo et al 2004) or binary lenses (Alcock et al 2001b;An et al 2002), or directly using highangular-resolution imaging and interferometry (e.g. Kozłowski et al 2007;Dong et al 2019;Cassan et al 2022) or astrometric microlensing (e.g. Sahu et al 2014Sahu et al , 2017Kains et al 2017;Rybicki et al 2018;Sahu et al 2022;Lam et al 2022).…”

Section: Timescale Distributionsmentioning

confidence: 99%

Gaia Data Release 3

Wyrzykowski¹,

Kruszynska²,

Rybicki³

2023

A&A

View full text Add to dashboard Cite

Context. One of the rarest types of variability is the phenomenon of gravitational microlensing, a transient brightening of a background star due to an intervening lensing object. Microlensing is a powerful tool for studying the invisible or otherwise undetectable populations in the Milky Way, including planets and black holes. Aims. We describe the first Gaia catalogue of candidate microlensing events, give an overview of its content, and discuss its validation. Methods. The catalogue of Gaia microlensing events was composed by analysing the light curves of around 2 billion sources of Gaia DR3 from all over the sky covering 34 months, between 2014 and 2017. Results. We present 363 Gaia microlensing events and discuss their properties. Of these, 90 have never been reported before and have not been discovered by other surveys. The contamination of the catalogue is assessed to 0.6%-1.7%.

show abstract

Section: Timescale Distributionsmentioning

confidence: 99%

Gaia Data Release 3

Wyrzykowski¹,

Kruszynska²,

Rybicki³

2023

A&A

View full text Add to dashboard Cite

show abstract

“…As the telescope moves in the image plane in the focal region of a stellar gravitational lens, the intensity pattern changes, yielding either of the four distributions. These expressions may be used to model the temporally evolving morphology of an Einstein ring that is formed on the image sensor (e.g., Cassan et al 2022). They can also be used to process imaging data and to recover parameters of interest regarding the lens and the source.…”

Section: Image Formation In the Strong Interference Regionmentioning

confidence: 99%

Evolving Morphology of Resolved Stellar Einstein Rings

Turyshev

Toth²

2023

ApJ

View full text Add to dashboard Cite

We consider strong gravitational lensing by nearby stars. Using our wave-optical treatment of lensing phenomena, we study Einstein rings that may form around nearby stellar lenses. It is remarkable that these rings are bright and large enough to be detected and resolved by existing instruments. Such lensing events have durations of hours or days, with peak light amplification lasting for several minutes. Many such events may be predicted using the Gaia astrometric catalog. Serendipitous discoveries are also possible. Fortuitous alignments can be used to confirm or discover and study exoplanets. For lenses that have dense stellar regions in their background, these events may occur several time a year, warranting their continuous or recurrent monitoring. Resolved imaging and spectroscopy of the evolving morphology of an Einstein ring offers knowledge about both the lens and the source. The angular size of the Einstein ring amounts to a direct measurement of the lens mass. The changing orientation of the major and minor images of the source offers astrometric information related to the mutual orientation of the objects. The event duration, when the full ring is present, helps to determine the source’s size. The sky position of planetary lensing events constrains the planet’s orbit. Spectroscopy of the ring allows for direct investigations of the source. The frequency and predictability of these events and the wealth of information that can be obtained by imaging motivate observational campaigns using existing facilities and/or construction of new instruments dedicated to the search and study of Einstein rings that are forming around nearby stars. As a specific example, we consider a predicted 2028 lensing of a red giant by α Centauri A and discuss the relevant science campaign.

show abstract

“…An alternative to finite-source effects, namely, precise mass-distance relations, can be obtained by high-resolution imaging, which works in a complementary way to the annual parallax, as it privileges fast-moving lenses (Bhattacharya et al 2018), but requires sufficiently bright lenses; otherwise, only the upper limits can be obtained. Measurements of θ E have been recently obtained by interferometry (Dong et al 2019;Cassan et al 2021), which may open very interesting perspectives for very bright sources. Finally, the astrometric detection of the centroid motion provides an alternative channel for space missions (Klüter et al 2020;Sahu et al 2022;Lam et al 2022).…”

Section: High-precision Mass Measurements By Microlensingmentioning

confidence: 99%

Precision measurement of a brown dwarf mass in a binary system in the microlensing event

Herald¹,

Udalski²,

Bozza³

et al. 2022

A&A

View full text Add to dashboard Cite

Context. Brown dwarfs are transition objects between stars and planets that are still poorly understood, for which several competing mechanisms have been proposed to describe their formation. Mass measurements are generally difficult to carry out for isolated objects as well as for brown dwarfs orbiting low-mass stars, which are often too faint for a spectroscopic follow-up. Aims. Microlensing provides an alternative tool for the discovery and investigation of such faint systems. Here, we present an analysis of the microlensing event OGLE-2019-BLG-0033/MOA-2019-BLG-035, which is caused by a binary system composed of a brown dwarf orbiting a red dwarf. Methods. Thanks to extensive ground observations and the availability of space observations from Spitzer, it has been possible to obtain accurate estimates of all microlensing parameters, including the parallax, source radius, and orbital motion of the binary lens. Results. Following an accurate modeling process, we found that the lens is composed of a red dwarf with a mass of M1 = 0.149 ± 0.010 M⊙ and a brown dwarf with a mass of M2 = 0.0463 ± 0.0031 M⊙ at a projected separation of a⊥ = 0.585 au. The system has a peculiar velocity that is typical of old metal-poor populations in the thick disk. A percent-level precision in the mass measurement of brown dwarfs has been achieved only in a few microlensing events up to now, but will likely become more common in the future thanks to the Roman space telescope.

show abstract

Microlensing mass measurement from images of rotating gravitational arcs

Cited by 18 publications

References 33 publications

Gaia Data Release 3

Gaia Data Release 3

Evolving Morphology of Resolved Stellar Einstein Rings

Precision measurement of a brown dwarf mass in a binary system in the microlensing event

Contact Info

Product

Resources

About