Ground-based variability surveys towards Centaurus A:: worthwhile or not?

被引:6
作者
de Jong, J. T. A. [1 ,2 ]
Kuijken, K. H. [2 ,3 ]
Heraudeau, P. [2 ,4 ]
机构
[1] Max Planck Inst Astron, D-69117 Heidelberg, Germany
[2] Univ Groningen, Kapteyn Astron Inst, NL-9700 AV Groningen, Netherlands
[3] Leiden Univ, Sterrewacht Leiden, NL-2300 RA Leiden, Netherlands
[4] Argelander Inst Astron, D-53121 Bonn, Germany
关键词
galaxies : individual : Centaurus A; galaxies : stellar content; stars : variables : general; gravitational lensing;
D O I
10.1051/0004-6361:20078378
中图分类号
P1 [天文学];
学科分类号
0704 [天文学];
摘要
Context. Difference imaging has proven to be a powerful technique for detecting and monitoring the variability of unresolved stellar sources in M 31. Using this technique in surveys of galaxies outside the Local Group could have many interesting applications. Aims. The goal of this paper is to test difference imaging photometry on Centaurus A, the nearest giant elliptical galaxy, at a distance of 4 Mpc. Methods. We obtained deep photometric data with the Wide Field Imager at the ESO/MPG 2.2 m at La Silla spread over almost two months. Applying the difference imaging photometry package DIFIMPHOT, we produced high-quality difference images and detected variable sources. The sensitivity of the current observational setup was determined through artificial residual tests. Results. In the resulting high-quality difference images, we detect 271 variable stars. We find a difference flux detection limit corresponding to m(R) similar or equal to 24.5. Based on a simple model of the halo of Centaurus A, we estimate that a ground-based microlensing survey would detect in the order of 4 microlensing events per year due to lenses in the halo. Conclusions. Difference imaging photometry works very well at the distance of Centaurus A and promises to be a useful tool for detecting and studying variable stars in galaxies outside the local group. For microlensing surveys, a higher sensitivity is needed than achieved here, which would be possible with a large ground-based telescope or space observatory with wide-field imaging capabilities.
引用
收藏
页码:755 / 762
页数:8
相关论文
共 29 条
[1]
A method for optimal image subtraction [J].
Alard, C ;
Lupton, RH .
ASTROPHYSICAL JOURNAL, 1998, 503 (01) :325-331
[2]
Image subtraction using a space-varying kernel [J].
Alard, C .
ASTRONOMY & ASTROPHYSICS SUPPLEMENT SERIES, 2000, 144 (02) :363-370
[3]
The MACHO project: Microlensing results from 5.7 years of Large Magellanic Cloud observations [J].
Alcock, C ;
Allsman, RA ;
Alves, DR ;
Axelrod, TS ;
Becker, AC ;
Bennett, DP ;
Cook, KH ;
Dalal, N ;
Drake, AJ ;
Freeman, KC ;
Geha, M ;
Griest, K ;
Lehner, MJ ;
Marshall, SL ;
Minniti, D ;
Nelson, CA ;
Peterson, BA ;
Popowski, P ;
Pratt, MR ;
Quinn, PJ ;
Stubbs, CW ;
Sutherland, W ;
Tomaney, AB ;
Vandehei, T ;
Welch, D .
ASTROPHYSICAL JOURNAL, 2000, 542 (01) :281-307
[4]
ARTYUKHINA NM, 1996, VIZIER ONLINE DATA C, P2205
[5]
Baade D., 1999, MESSENGER, V95, P15
[6]
Microlensing surveys of M31 in the wide-field imaging era [J].
Baltz, EA .
ASTROPHYSICAL JOURNAL, 2005, 624 (01) :168-177
[7]
Microlensing candidates in M87 and the Virgo Cluster with the Hubble Space Telescope [J].
Baltz, EA ;
Lauer, TR ;
Zurek, DR ;
Gondolo, P ;
Shara, MM ;
Silk, J ;
Zepf, SE .
ASTROPHYSICAL JOURNAL, 2004, 610 (02) :691-706
[8]
Event rates and timescale distributions from realistic microlensing models of M31 [J].
Baltz, EA ;
Gyuk, G ;
Crotts, A .
ASTROPHYSICAL JOURNAL, 2003, 582 (01) :30-36
[9]
SExtractor: Software for source extraction [J].
Bertin, E ;
Arnouts, S .
ASTRONOMY & ASTROPHYSICS SUPPLEMENT SERIES, 1996, 117 (02) :393-404
[10]
BUZZONI A, 1993, ASTRON ASTROPHYS, V275, P433