Mid-IR Pure Rotational Emission from Young Stars: The TEXES/IRTF Survey
نویسندگان
چکیده
We describe the TEXES survey for mid-IR H2 pure rotational emission from young stars and report early successes. H2 emission is a potential tracer of warm gas in circumstellar disks. Three pure rotational lines are available from the ground: the J= 3⇒ 1, J=4⇒ 2, and J= 6⇒ 4, transitions at 17.035 μm, 12.279 μm, and 8.025μm, respectively. Using TEXES at the NASA IRTF 3m, we are midway through a survey of roughly 30 pre-main-sequence stars. To date, detected lines are all resolved, generally with FWHM<10 km/s. Preliminary analysis suggests the gas temperatures are between 400 and 800 K. From the work so far, we conclude that high spectral and spatial resolution are critical to the investigation of H2 in disks.
منابع مشابه
A search for H2 around pre-main-sequence stars
We present the results of a search for pure rotational molecular hydrogen emission from two pre-main-sequence stars, AB Aur and CQ Tau. Observations were made using MICHELLE, the mid-IR echelle spectrometer at the UK Infrared Telescope. We found some evidence for emission in the J = 4→ 2 line in AB Aur, but no J = 3→ 1 line from either star. We derive upper limits on line flux which are signifi...
متن کاملPre-Main-Sequence Stars with Photometric Rotation Periods
We use mid-IR (primarily 10 μm) photometry as a diagnostic for the presence of disks with inner cavities among 32 pre-main sequence stars in Orion and Taurus-Auriga for which rotation periods are known and which do not show evidence for inner disks at near-IR wavelengths. Disks with inner cavities are predicted by magnetic disk-locking models that seek to explain the regulation of angular momen...
متن کاملLooking for Pure Rotational H2 Emission from Protoplanetary Disks
We report on a limited search for pure rotational molecular hydrogen emission associated with young, pre–mainsequence stars. We looked for H2 , and emission in the mid-infrared using the Texas v p 0 J p 3 r 1 4 r 2 Echelon Cross Echelle Spectrograph at NASA’s 3 m Infrared Telescope Facility. The high spectral and spatial resolutions of our observations lead to more stringent limits on narrow-li...
متن کاملSpitzer Observations of the Hh 1/2 System. the Discovery of the Counterjet
We present unpublished Spitzer IRAC observations of the HH 1/2 young stellar outflow processed with a high angular resolution deconvolution algorithm , that produces sub-arcsecond (∼ 0.6 0.8′′) images. In the resulting mid-infrared images, the optically invisible counterjet is detected for the first time. The counterjet is approximately half as bright as the jet at 4.5μm (the IRAC band that bes...
متن کاملThe RMS Survey: A Systematic Search for Massive Young Stars in the Galaxy
We have selected red MSX sources (RMS) that have the colours of massive young stellar objects (MYSOs). Our aim is to generate a large, systematically selected sample to address questions such as their luminosity function, lifetimes, clustering and triggering. Other objects such as UCHIIs, PN, PPN and AGB stars have similar IR colours and a large programme of ground-based follow-up observations ...
متن کامل