VVV Survey Microlensing Events in the Galactic Center Region

María Gabriela Navarro, Dante Minniti, Rodrigo Contreras Ramos

Resultado de la investigación: Review article

3 Citas (Scopus)

Resumen

We search for microlensing events in the highly reddened areas surrounding the Galactic center using the near-IR observations with the VISTA Variables in the Vía Láctea Survey (VVV). We report the discovery of 182 new microlensing events, based on observations acquired between 2010 and 2015. We present the color-magnitude diagrams of the microlensing sources for the VVV tiles b332, b333, and b334, which were independently analyzed, and show good qualitative agreement among themselves. We detect an excess of microlensing events in the central tile b333 in comparison with the other two tiles, suggesting that the microlensing optical depth keeps rising all the way to the Galactic center. We derive the Einstein radius crossing time for all of the observed events. The observed event timescales range from t E = 5 to 200 days. The resulting timescale distribution shows a mean timescale of days for the complete sample (N = 182 events), and days if restricted only for the red clump (RC) giant sources (N = 96 RC events). There are 20 long timescale events ( days) that suggest the presence of massive lenses (black holes) or disk-disk event. This work demonstrates that the VVV Survey is a powerful tool to detect intermediate/long timescale microlensing events in highly reddened areas, and it enables a number of future applications, from analyzing individual events to computing the statistics for the inner Galactic mass and kinematic distributions, in aid of future ground- and space-based experiments.

Idioma originalEnglish
Número de artículoL13
PublicaciónAstrophysical Journal Letters
Volumen851
N.º1
DOI
EstadoPublished - 10 dic 2017

Huella dactilar

timescale
tiles
clumps
optical depth
kinematics
diagram
galactic mass
color-magnitude diagram
mass distribution
optical thickness
experiment
lenses
statistics
distribution
radii

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Citar esto

Navarro, María Gabriela ; Minniti, Dante ; Ramos, Rodrigo Contreras. / VVV Survey Microlensing Events in the Galactic Center Region. En: Astrophysical Journal Letters. 2017 ; Vol. 851, N.º 1.
@article{4c30eece148344bd8c570c84f82c80f2,
title = "VVV Survey Microlensing Events in the Galactic Center Region",
abstract = "We search for microlensing events in the highly reddened areas surrounding the Galactic center using the near-IR observations with the VISTA Variables in the V{\'i}a L{\'a}ctea Survey (VVV). We report the discovery of 182 new microlensing events, based on observations acquired between 2010 and 2015. We present the color-magnitude diagrams of the microlensing sources for the VVV tiles b332, b333, and b334, which were independently analyzed, and show good qualitative agreement among themselves. We detect an excess of microlensing events in the central tile b333 in comparison with the other two tiles, suggesting that the microlensing optical depth keeps rising all the way to the Galactic center. We derive the Einstein radius crossing time for all of the observed events. The observed event timescales range from t E = 5 to 200 days. The resulting timescale distribution shows a mean timescale of days for the complete sample (N = 182 events), and days if restricted only for the red clump (RC) giant sources (N = 96 RC events). There are 20 long timescale events ( days) that suggest the presence of massive lenses (black holes) or disk-disk event. This work demonstrates that the VVV Survey is a powerful tool to detect intermediate/long timescale microlensing events in highly reddened areas, and it enables a number of future applications, from analyzing individual events to computing the statistics for the inner Galactic mass and kinematic distributions, in aid of future ground- and space-based experiments.",
keywords = "galaxy: bulge, galaxy: structure, gravitational lensing: micro",
author = "Navarro, {Mar{\'i}a Gabriela} and Dante Minniti and Ramos, {Rodrigo Contreras}",
year = "2017",
month = "12",
day = "10",
doi = "10.3847/2041-8213/aa9b29",
language = "English",
volume = "851",
journal = "Astrophysical Journal Letters",
issn = "2041-8205",
publisher = "IOP Publishing Ltd.",
number = "1",

}

VVV Survey Microlensing Events in the Galactic Center Region. / Navarro, María Gabriela; Minniti, Dante; Ramos, Rodrigo Contreras.

En: Astrophysical Journal Letters, Vol. 851, N.º 1, L13, 10.12.2017.

Resultado de la investigación: Review article

TY - JOUR

T1 - VVV Survey Microlensing Events in the Galactic Center Region

AU - Navarro, María Gabriela

AU - Minniti, Dante

AU - Ramos, Rodrigo Contreras

PY - 2017/12/10

Y1 - 2017/12/10

N2 - We search for microlensing events in the highly reddened areas surrounding the Galactic center using the near-IR observations with the VISTA Variables in the Vía Láctea Survey (VVV). We report the discovery of 182 new microlensing events, based on observations acquired between 2010 and 2015. We present the color-magnitude diagrams of the microlensing sources for the VVV tiles b332, b333, and b334, which were independently analyzed, and show good qualitative agreement among themselves. We detect an excess of microlensing events in the central tile b333 in comparison with the other two tiles, suggesting that the microlensing optical depth keeps rising all the way to the Galactic center. We derive the Einstein radius crossing time for all of the observed events. The observed event timescales range from t E = 5 to 200 days. The resulting timescale distribution shows a mean timescale of days for the complete sample (N = 182 events), and days if restricted only for the red clump (RC) giant sources (N = 96 RC events). There are 20 long timescale events ( days) that suggest the presence of massive lenses (black holes) or disk-disk event. This work demonstrates that the VVV Survey is a powerful tool to detect intermediate/long timescale microlensing events in highly reddened areas, and it enables a number of future applications, from analyzing individual events to computing the statistics for the inner Galactic mass and kinematic distributions, in aid of future ground- and space-based experiments.

AB - We search for microlensing events in the highly reddened areas surrounding the Galactic center using the near-IR observations with the VISTA Variables in the Vía Láctea Survey (VVV). We report the discovery of 182 new microlensing events, based on observations acquired between 2010 and 2015. We present the color-magnitude diagrams of the microlensing sources for the VVV tiles b332, b333, and b334, which were independently analyzed, and show good qualitative agreement among themselves. We detect an excess of microlensing events in the central tile b333 in comparison with the other two tiles, suggesting that the microlensing optical depth keeps rising all the way to the Galactic center. We derive the Einstein radius crossing time for all of the observed events. The observed event timescales range from t E = 5 to 200 days. The resulting timescale distribution shows a mean timescale of days for the complete sample (N = 182 events), and days if restricted only for the red clump (RC) giant sources (N = 96 RC events). There are 20 long timescale events ( days) that suggest the presence of massive lenses (black holes) or disk-disk event. This work demonstrates that the VVV Survey is a powerful tool to detect intermediate/long timescale microlensing events in highly reddened areas, and it enables a number of future applications, from analyzing individual events to computing the statistics for the inner Galactic mass and kinematic distributions, in aid of future ground- and space-based experiments.

KW - galaxy: bulge

KW - galaxy: structure

KW - gravitational lensing: micro

UR - http://www.scopus.com/inward/record.url?scp=85039158047&partnerID=8YFLogxK

U2 - 10.3847/2041-8213/aa9b29

DO - 10.3847/2041-8213/aa9b29

M3 - Review article

AN - SCOPUS:85039158047

VL - 851

JO - Astrophysical Journal Letters

JF - Astrophysical Journal Letters

SN - 2041-8205

IS - 1

M1 - L13

ER -