|Disk masses for virgul10 Myr old brown dwarf disks
|We request SPIRE 200-500mu observations for two brown dwarf disks, 2MASSW J1207334-393254 (2M1207) and SSSPM J1102-3431 (SSSPM 1102), in the TW Hydrae Association (TWA). From our previous Spitzer observations, we had confirmed excess emission at wavelengths of virgul5-38mu for both of these sources. With the SPIRE observations, we can probe the optically thin dust in the outer cooler regions of these disks. We have performed radiative transfer modeling for these systems. With the available mid-infrared observations, we find high degeneracies for the disk mass and outer disk radius estimates. Observations at far-infrared wavelengths can help constrain the model fits and obtain better estimates for the disk mass and outer radius for these disks. At an age of virgul10 Myr, 2M1207 and SSSPM1102 are the oldest known brown dwarf disks. It is thus important to estimate the disk masses for these older disks, and to understand, in comparison with the younger Taurus systems, if brown dwarf disk masses show any decline with the age of the system. We also request PACS 70mu photometry for another candidate brown dwarf disk in the TWA, 2MASSW J1139511-315921 (2M1139). This object shows an excess emission at 24mu, but none at shorter wavelengths. With 70mu observations, we can confirm if the disk flares up at longer wavelengths. If the presence of such a disk is confirmed for 2M1139, then this would be the first transition disk detected among the sub-stellar members of TWA.
|Herschel SPIRE observations of the TWA brown dwarf disc 2MASSW J1207334-393254 . Riaz B. et al. . Monthly Notices of the Royal Astronomical Society: Letters, Volume 422, Issue 1, pp. L6-L10. . 422 . 10.1111/j.1745-3933.2012.01225.x . 2012MNRAS.422L...6R ,
Herschel PACS and SPIRE observations of TW Hydrae association brown dwarf disks . Riaz B. et al. . Astronomy & Astrophysics, Volume 548, id.A54, 7 pp. . 548 . 10.1051/0004-6361/201219524 . 2012A&A...548A..54R ,
|Herschel was launched on 14 May 2009! It is the fourth 'cornerstone' mission in the ESA science programme. With a 3.5 m Cassegrain telescope it is the largest space telescope ever launched. It is performing photometry and spectroscopy in approximately the 55-671 µm range, bridging the gap between earlier infrared space missions and groundbased facilities.
|Publisher And Registrant
|European Space Agency
|European Space Agency, 2012, OT1_briaz_4, SPG v14.2.0. https://doi.org/10.5270/esa-jkpib62