Saved in:
Bibliographic Details
Main Authors: Zelakiewicz, Aiden S., Johnson, Samson A., Gaudi, B. Scott, Bryden, Geoffrey, Nataf, David M., Shvartzvald, Yossi
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2509.25440
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866914169136087040
author Zelakiewicz, Aiden S.
Johnson, Samson A.
Gaudi, B. Scott
Bryden, Geoffrey
Nataf, David M.
Shvartzvald, Yossi
author_facet Zelakiewicz, Aiden S.
Johnson, Samson A.
Gaudi, B. Scott
Bryden, Geoffrey
Nataf, David M.
Shvartzvald, Yossi
contents The Galactic bulge is one of the most information-dense regions to study resolved stellar populations, variables, and transients, such as microlensing events. Studies toward the Galactic bulge are complicated by the large and variable extinction along the line of sight. We measure the near-infrared $A_{K_S}$ extinction and $E(H-K_S)$ reddening in this region using $H$- and $K$-band photometry obtained with the 2017 UKIRT microlensing survey. We fit the apparent magnitude and color distribution of bright giants in the bulge to recover the apparent magnitude and color of Red Clump stars, which are known to be standard candles and crayons. We present $2^\prime \times 2^\prime$ resolution maps in UKIRT fields between $-2.15^{\circ} \le l \le 2.71^{\circ}$ and $-2.69^{\circ} \le b \le 2.03^{\circ}$ of the $A_{K_S}$ extinction and the $E(H-K_S)$ reddening. We find large variations in the $K_S$-band extinction and $E(H-K_S)$ reddening on all the scales we probe. We find that a constant, standard extinction law is a poor representation of the relationship between the extinction and reddening we measure in fields of different latitudes. These maps will be useful for understanding the near-infrared extinction law for sight lines close to the Galactic plane, as well as for final field selection for the Nancy Grace Roman Space Telescope Galactic Bulge Time Domain Survey.
format Preprint
id arxiv_https___arxiv_org_abs_2509_25440
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle A Near-Infrared Extinction and Reddening Map Towards the Galactic Bulge Using UKIRT
Zelakiewicz, Aiden S.
Johnson, Samson A.
Gaudi, B. Scott
Bryden, Geoffrey
Nataf, David M.
Shvartzvald, Yossi
Astrophysics of Galaxies
The Galactic bulge is one of the most information-dense regions to study resolved stellar populations, variables, and transients, such as microlensing events. Studies toward the Galactic bulge are complicated by the large and variable extinction along the line of sight. We measure the near-infrared $A_{K_S}$ extinction and $E(H-K_S)$ reddening in this region using $H$- and $K$-band photometry obtained with the 2017 UKIRT microlensing survey. We fit the apparent magnitude and color distribution of bright giants in the bulge to recover the apparent magnitude and color of Red Clump stars, which are known to be standard candles and crayons. We present $2^\prime \times 2^\prime$ resolution maps in UKIRT fields between $-2.15^{\circ} \le l \le 2.71^{\circ}$ and $-2.69^{\circ} \le b \le 2.03^{\circ}$ of the $A_{K_S}$ extinction and the $E(H-K_S)$ reddening. We find large variations in the $K_S$-band extinction and $E(H-K_S)$ reddening on all the scales we probe. We find that a constant, standard extinction law is a poor representation of the relationship between the extinction and reddening we measure in fields of different latitudes. These maps will be useful for understanding the near-infrared extinction law for sight lines close to the Galactic plane, as well as for final field selection for the Nancy Grace Roman Space Telescope Galactic Bulge Time Domain Survey.
title A Near-Infrared Extinction and Reddening Map Towards the Galactic Bulge Using UKIRT
topic Astrophysics of Galaxies
url https://arxiv.org/abs/2509.25440