1. Inner warm disk of Class I ESO Hα 279a revealed by Na I and CO overtone emission lines
A-Ran Lyo, Jongsoo Kim, Jae-Joon Lee, Kyoung-Hee Kim, Jihyun Kang, Do-Young Byun, Gregory Mace, Kimberly R. Sokal, Chan Park, Moo-Young Chun, Heeyoung Oh, Young Sam Yu, Jae Sok Oh, Ueejeong Jeong, Hwihyun Kim, Soojong Pak, Narae Hwang, Byeong-Gon Park, Sungho Lee, Kyle Kaplan, Hye-In Lee, Huynh Anh Nguyen Le, and Daniel Jaffe
IGRINS (Immersion GRating INfrared Spectrometer)
R = λ/Δλ = 45,000
Simultaneous observation of H & K
Δv ~ 7 km/s at 2.3 μm
Mounted on 2.7m MacDonald telescope
Current: 4.3m DCT (discovery channel telescope)
IGRINS mounted on 2.7m MacDonald Telescope

2. (Andrews et al. 2016, ApJL, 820, L40)

3. Inner disk : main controller of the final structure of planetary systems

4. ESO Hα 279a
Class I YSO (Young stellar object) in Serpens Molecular Clouds
d = 429 pc (Dzib et al. 2010, 2011)
M ~ 1.5 M⊙

5. H-band

6. K-band

7. 1. Inner warm CO gas disk
Geometrically flat Keplerian rotational CO disk with the power law distributions in density and temperature
Density index p = 1.5, temperature index q= 0.5
Nin = 2.275×1018/cm2; Tin = 4600; Vin sini = 55.5 km/s; Vout sini = 15.0 km/s
R ~ 0.22 – 3.00 AU at M=1.5M⊙ at the disk inclination of 45°

8. 2. Inner warm Na I keplerian rotational disk
Power index in the density distribution p = 1.5 (p = 2.0)
R1/R2 = 0.03 (0.08)
V2 sini = km/s (28.42 km/s)
R ~ 0.02 – 0.72 AU (0.07 – 0.83 AU)

9. 3. Extinction Stellar properties – Disk properties
Extinction – Stellar properties, such as mass, age, etc.
Av = 9.6 mag (Class II/III YSOs) at Serpens star forming region
Brackett series: Av = 9.7 mag
case B model recombination emissivities at the condition of T=7500 K and ne=108 cm−3
(Storey & Hummer 1995)

10. 4. Disk Accretion rate
Ṁacc ∼ 2 – 10 × 10-7 M⊙/yr
FK ~ 4.63×10-10 erg sec-1 cm-2 μm-1
EW = Å
It follows the derived relationships between the stellar masses and
the mass accretion rates of Ṁacc ∝ M2.1 (Muzerolle et al. 2005)

11. Class I ESO Hα 279a
we detect emission lines originating from the accretion channel flow, jet,
and inner disk
: hydrogen Brackett series recombination, [Fe II], [Fe III], [Fe IV], Ca I, Na I,
H2, H2O and CO overtone emission lines.
CO overtone emission lines originated in the keplerian disk in the range
between 0.22 AU and 3.00 AU.
Na I emission lines originate between 0.04 AU and 0.78 AU
we confirm that the mean extinction value of AV = 9.6 mag for Class II/III YSOs
in the Serpens region also matches our estimation towards ESO Hα 279a.
Ṁ = 2 ∼ 10 × 10−7 M⊙ yr−1 from the measured Brγ emission luminosity
of 1.78×1031 erg s−1.