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NICMOS coronagraphic observations of the GM Aurigae circumstellar disk

Schneider, G. and Wood, K. and Silverstone, M. D. and Hines, D. C. and Koerner, D. W. and Whitney, B. A. and Bjorkman, J. E. and Lowrance, P. J. (2003) NICMOS coronagraphic observations of the GM Aurigae circumstellar disk. Astronomical Journal, 125 (3). pp. 1467-1479. ISSN 1538-3881


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Publisher’s or external URL: http://dx.doi.org/10.1086/367596


We present Hubble Space Telescope Near Infrared Camera and Multi-Object Spectrometer (NICMOS) coronagraphic observations of the environment in the region of the young star-disk system GM Aurigae. Scattered near-infrared light in two spectral bands (F110W = 1.1 mum and F160W = 1.6 mum) trace the morphology of circumstellar dust to a distance of similar to700 AU from the star. An similar to300 AU radius outwardly flared disk inclined 50degrees-55degrees to the plane of the sky surrounded by a tenuous envelope is seen in the NICMOS images, confirming the size and suspected flared nature of the disk suggested by earlier CO and optical observations. The NICMOS images probe the disk region with spatial resolutions of similar to0."1 at radial distances of 0."35 to similar to4."5-5."0 from the largely unobscured (A(v) < 0.5) central star. The midplane of the disk 1.&DPRIME;3 from GM Aurigae is revealed in silhouette against the previously unseen lower portion of the illuminated disk along its minor axis ( as projected onto the sky). We comment on surface brightness profiles along the disk major and minor axes, as well as isophotal maps of the disk. From these photometric data we have measured the integrated flux density of the disk, beyond the instrumental inner radius of 0.&DPRIME;35, as 8.0 and 9.3 mJy (+/-20%) at F110W and F160W, respectively, corresponding to disk scattering fractions of L-disk/L* = 0.025 (+/-20%) in both bands. By fitting the photometric properties of the disk to a scattered-light model, we estimate the disk mass to be &SIM;0.04 M-.. Additionally, we find two diffuse red polar lobes along the disk minor axis, likely the result of a bipolar outflow, at distances of +/-3.&DPRIME;8 from GM Aurigae (&SIM;900 AU with our inferred inclination) with peak H-band surface brightnesses of &SIM;14 &mu;Jy arcsec(-2). We also note the existence of a broad (&SIM;3&DPRIME; wide) band of blue material within the NICMOS field of view, spatially coincident with and extending at least 12&DPRIME; from the northeast outer region of the disk major axis.

Item Type: Article
Publisher’s Statement: © 2003 American Astronomical Society.
ID number or DOI: 10.1086/367596
Keywords: accretion disks; binary-systems; circumstellar matter; main-sequence stars; model scattering envelopes; nearby stars; orion population; spectral energy-distributions; stars : individual (GM Aurigae); t-tauri stars; ultraviolet extinction; young stellar objects
Subjects: Q Science > QB Astronomy
NAU Depositing Author Academic Status: Faculty/Staff
Department/Unit: College of Engineering, Forestry, and Natural Science > Physics and Astronomy
Date Deposited: 30 Sep 2015 16:46
URI: http://openknowledge.nau.edu/id/eprint/379

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