2009ApJ...696.1407N


Query : 2009ApJ...696.1407N

2009ApJ...696.1407N - Astrophys. J., 696, 1407-1417 (2009/May-2)

Interstellar extinction law toward the Galactic Center III: J, H, KSBands in the 2MASS and the MKO systems, and 3.6, 4.5, 5.8, 8.0 µm in the Spitzer/IRAC system.

NISHIYAMA S., TAMURA M., HATANO H., KATO D., TANABE T., SUGITANI K. and NAGATA T.

Abstract (from CDS):

We have determined interstellar extinction law toward the Galactic center (GC) at the wavelength from 1.2 to 8.0 µm, using point sources detected in the IRSF/SIRIUS near-infrared (NIR) survey and those in the Two Micron All Sky Survey (2MASS) and Spitzer/IRAC/GLIMPSE II catalogs. The central region {mid}l {mid} ≲3°.0 and {mid}b {mid} ≲1°.0 has been surveyed in the J, H, and KS bands with the IRSF telescope and the SIRIUS camera whose filters are similar to the Mauna Kea Observatories (MKO) NIR photometric system. Combined with the GLIMPSE II point source catalog, we made KSversus KS- λ color-magnitude diagrams (CMDs) where λ=3.6, 4.5, 5.8, and 8.0 µm. The KS magnitudes of bulge red clump stars and the KS- λ colors of red giant branches are used as a tracer of the reddening vector in the CMDs. From these magnitudes and colors, we have obtained the ratios of total-to-selective extinction for the four IRAC bands. Combined with for the J and H bands derived by Nishiyama et al., we obtain AJ :AH::A[3.6]:A[4.5]:A[5.8]:A[8.0]= 3.02:1.73:1:0.50:0.39:0.36:0.43 for the line of sight toward the GC. This confirms the flattening of the extinction curve at λ ≳ 3 µm from a simple extrapolation of the power-law extinction at shorter wavelengths, in accordance with recent studies. The extinction law in the 2MASS J, H, and KS bands has also been calculated, and good agreement with that in the MKO system is found. Thus, it is established that the extinction in the wavelength range of J, H, and KS is well fitted by a power law of steep decrease Aλ∝ λ–2.0 toward the GC. In nearby molecular clouds and diffuse interstellar medium, the lack of reliable measurements of the total-to-selective extinction ratios hampers unambiguous determination of the extinction law; however, observational results toward these lines of sight cannot be reconciled with a single extinction law.

Abstract Copyright:

Journal keyword(s): dust, extinction - Galaxy: center - infrared: ISM - stars: horizontal-branch

Simbad objects: 14

goto Full paper

goto View the references in ADS

Number of rows : 14
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2023
#notes
1 NGC 2024 Cl* 05 41 43 -01 50.5           ~ 1123 1
2 M 78 RNe 05 46 45.8 +00 04 45   8.0       ~ 366 0
3 NAME Cha 1 MoC 11 06 48 -77 18.0           ~ 1095 1
4 NAME Coalsack G2 MoC 12 31 29 -63 44.8           ~ 39 0
5 * omi Sco V* 16 20 38.1806792 -24 10 09.549111 5.99 5.40 4.57 3.69 2.93 A5II 249 0
6 NAME Ophiuchus Molecular Cloud SFR 16 28 06 -24 32.5           ~ 3446 1
7 LDN 1746 DNe 17 11.3 -27 22           ~ 127 0
8 NAME Galactic Center reg 17 45 39.60213 -29 00 22.0000           ~ 13430 0
9 NAME Sgr A* X 17 45 40.03599 -29 00 28.1699           ~ 4041 3
10 NAME Quintuplet Cluster OpC 17 46 13.9 -28 49 48           ~ 502 0
11 NAME Baade Window reg 18 03.5 -30 01           ~ 586 3
12 NAME Serpens Cloud SFR 18 29 49 +01 14.8           ~ 1049 2
13 Ass Cyg OB 2 As* 20 33.2 +41 19           ~ 890 0
14 NAME Galactic Bulge reg ~ ~           ~ 4012 0

To bookmark this query, right click on this link: simbad:objects in 2009ApJ...696.1407N and select 'bookmark this link' or equivalent in the popup menu


2023.01.30-06:07:37

© Université de Strasbourg/CNRS

    • Contact