The complex, variable near infrared extinction towards the Nuclear Bulge

Abstract

Using deep J, H and Ks-band observations, we have studied the near-infrared (nIR) extinction of the Nuclear Bulge (NB) and we find significant, complex variations on small physical scales. We have applied a new variable nIR colour excess method, V-NICE, to measure the extinction; this method allows for variation in both the extinction law parameter alpha and the degree of absolute extinction on very small physical scales. We see significant variation in both these parameters on scales of 5 arcsec. In our observed fields, representing a random sample of sight lines to the NB, we measure alpha to be 2.64 +- 0.52, compared to the canonical "universal" value of 2. Our measured levels of A_Ks are similar to previously measured results (1 < A_Ks < 4.5); however, the steeper extinction law results in higher values for A_J (4.5 < A_J < 10) and A_H (1.5 < A_H < 6.5). Only when the extinction law is allowed to vary on the smallest scales can we recover self-consistent measures of the absolute extinction at each wavelength, allowing accurate reddening corrections for field star photometry in the NB. The steeper extinction law slope also suggests that previous conversions of nIR extinction to A_V may need to be reconsidered. Finally, we find that the measured values of extinction are significantly dependent on the filter transmission functions of the instrument used to obtain the data. This effect must be taken into account when combining or comparing data from different instruments.

8 pages, 4 figurs, 1 table, published in MNRAS

References in corpus (17)

• Interstellar Dust Grains
• A Quantitative Comparison of SMC, LMC, and Milky Way UV to NIR Extinction Curves
• An Analysis of the Shapes of Interstellar Extinction Curves. V. The IR-Through-UV Curve Morphology
• Mapping the interstellar dust with near-infrared observations: An optimized multi-band technique
• Interstellar Extinction Law in the J, H, and Ks Bands toward the Galactic Center
• Low-extinction windows in the inner Galactic Bulge
• Interstellar Extinction Law toward the Galactic Center II: V, J, H, and Ks Bands
• JHKL Photometry and the K-band Luminosity Function at the Galactic Center
• The Optical Gravitational Lensing Experiment. Is Interstellar Extinction Toward the Galactic Center Anomalous?
• Extinction within 10 degrees of the Galactic Centre using 2MASS
• 86 GHz SiO maser survey of late-type stars in the Inner Galaxy III. Interstellar extinction and colours of the SiO targets
• A large scale extinction map of the Galactic Anticenter from 2MASS
• GRO J1744-28, search for the counterpart: infrared photometry and spectroscopy
• ISO observations of the Galactic center Interstellar Medium: ionized gas
• Extinction techniques and impact on dust property determination
• Complex small-scale structure in the infrared extinction towards the Galactic Centre
• An Infrared Imaging Survey of the Faint Chandra Sources near the Galactic Centre

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