IGRINS spectroscopy of Class I sources: IRAS 03445+3242 and IRAS 04239+2436

Abstract

We have detected molecular and atomic line emission from the hot and warm disks of two Class I sources, IRAS 03445+3242 and IRAS 04239+2436 using the high resolution Immersion GRating INfrared Spectrograph (IGRINS). CO overtone band transitions and near-IR lines of Na I and Ca I, all in emission, trace the hot inner disk while CO rovibrational absorption spectra of the first overtone transition trace the warm gas within the inner few AU of the disk. The emission-line profiles for both sources show evidence for Keplerian disks. A thin Keplerian disk with power-law temperature and column density profiles with a projected rotational velocity of $\sim$60--75 km s${}^{-1}$ and a gas temperature of $\sim$3500 K at the innermost annulus can reproduce the CO overtone band emission. Na I and Ca I emission lines also arise from this disk, but they show complicated line features possibly affected by photospheric absorption lines. Multi-epoch observations show asymmetric variations of the line profiles on one-year (CO overtone bandhead and atomic lines for IRAS 03445+3242) or on one-day (atomic lines for IRAS 04239+2436) time scales, implying non-axisymmetric features in disks. The narrow CO rovibrational absorption spectra ($v$=0$\to$2) indicate that both warm ($>$ 150 K) and cold ($\sim$20--30 K) CO gas are present along the line of sight to the inner disk. This study demonstrates the power of IGRINS as a tool for studies of the sub-AU scale hot and AU-scale warm protoplanetary disks with its simultaneous coverage of the full H and K bands with high spectral resolution ($R$= 45,000) allowing many aspects of the sources to be investigated at once.

Accepted for publication in ApJ

References in corpus (15)

• The relation between gas and dust in the Taurus Molecular Cloud
• The N2D+/N2H+ ratio as an evolutionary tracer of Class 0 protostars
• The Evolution of the Multiplicity of Embedded Protostars I: Sample Properties and Binary Detections
• The Relationship between the Optical Depth of the 9.7 micron Silicate Absorption Feature and Infrared Differential Extinction in Dense Clouds
• Accretion and ejection properties of embedded protostars: the case of HH26, HH34 and HH46 IRS
• High-precision C17O, C18O and C16O measurements in young stellar objects: analogues for CO self-shielding in the early solar system
• Investigating the inner discs of Herbig Ae/Be stars with CO bandhead and Br Gamma emission
• The structure of disks around Herbig Ae/Be stars as traced by CO ro-vibrational emission
• Constraining the Sub-AU-Scale Distribution of Hydrogen and Carbon Monoxide Gas around Young Stars with the Keck Interferometer
• Spatially resolving the hot CO around the young Be star 51 Ophiuchi
• Stellar and Circumstellar Properties of the Pre-Main Sequence Binary GV Tau from Infrared Spectroscopy
• Dust Stratification in Young Circumstellar Disks
• A spider-like outflow in Barnard 5 - IRS 1: The transition from a collimated jet to a wide-angle outflow?
• Near-IR Spectroscopic Monitoring of Class I Protostars: Variability of Accretion and Wind Indicators
• Herschel Key Program, "Dust, Ice, and Gas In Time" (DIGIT): the origin of molecular and atomic emission in low-mass protostars in Taurus

Cited by in corpus (9)

• Diagnosing FUor-like Sources: The Parameter Space of Viscously Heated Disks in the Optical and Near-IR
• Dissecting the different components of the modest accretion bursts of the very young protostar HOPS 373
• Fluorescent H_2 Emission Lines from the Reflection Nebula NGC 7023 Observed with IGRINS
• Triple spiral arms of a triple protostar system imaged in molecular lines
• High-Resolution Mid-Infrared Spectroscopy of GV Tau N: Surface Accretion and Detection of Ammonia in a Young Protoplanetary Disk
• 10 Years of Archival High-Resolution NIR Spectra: The Raw and Reduced IGRINS Spectral Archive (RRISA)
• The role of detailed gas and dust opacities in shaping the evolution of the inner disc edge subject to episodic accretion
• The GRAVITY Young Stellar Object survey IV. The CO overtone emission in 51 Oph at sub-au scales
• Evidence of Accretion Burst: The Viscously Heated Inner Disk of the Embedded Protostar IRAS 16316-1540