Ionized and Molecular Gases in Monoceros R2 Hwihyun Kim IGRINS Science Workshop November 1213 2015 Collaborators John Lacy amp Dan Jaffe Mon R2 RA6 h 7 m Dec623 Reflection ID: 626134
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Kinematic Study of Ionized and Molecular Gases in Monoceros R2
Hwihyun KimIGRINS Science WorkshopNovember 12-13, 2015
Collaborators: John Lacy & Dan JaffeSlide2
Mon R2 (RA=6h7m, Dec=-6°23’)
Reflection nebulae at D=830pc3-4 HII regions in the center embedded in molecular cloudsMon R2 CoreUltra compact HII regionSurrounded by several PhotoDissociation Regions (PDRs)~15’x15’ JHK composite of SQUID images at KPNO 1.3m (Carpenter et al. 1997)Slide3
Mon R2: closest Ultra Compact HII (UCHII) Region
Diameter=24” or 0.1 pc (measured using 12.8μm [Ne II] map)n(H2)= a few 105-106 cm-3IRAS 1SW: main ionizing source, B0 to O9.5 typeSlide4
UCHII regionsMorphology
: cometary, core-halo, shell, irregular, and multiple peaks (Wood & Churchwell, 1989).Lifetime “problem”: If UCHII regions are classical pressure-driven spherical shells (Vexp~10km/s), they should remain compact only for ~104 yr. HOWEVER most of detected UCHII regions are ~105 yr old!Slide5
Previous Studies using 12.8μm [Ne II] emissionby Jaffe et al. (2003) & Zhu et al. (2005, 2008)
of 16 UCHII regions with TEXES at IRTF suggestUCHII region morphologies are the same: systematic surface flows, rather than turbulence or bulk expansionSignificant velocity gradients (~5-20 km/s)Limb-brightened: up against dense neutral gasthese wind-driven cometary shells could have much longer lifetimeNeed to find the evidence for dense molecular gas along the shell wall! Are they moving along with the ionized gas? Or, slowly expanding?Slide6
IGRINS ObservationsDec 29, 20142x300sec exposure on each slit position
(6 pointings)Slit off-on-on-off mode IGRINS H & K SpectraTotal 600 secSlide7
Preliminary Results IGRINS PLP-2.1-alpha.2 by Jae-
Joon LeePlotspec by Kyle KaplanSlide8
IRS1 - Center
H2Brγ[Fe III]
He ISlide9
IRS1 – SE1
H2Brγ[Fe III]
He ISlide10
IRS1 – SE2
H2Brγ[Fe III]
He ISlide11
IRS1 – SE3
H2Brγ[Fe III]
He ISlide12
IRS1 – SE4
H2Brγ[Fe III]
He ISlide13
IRS1 – SE5
H2Brγ[Fe III]
He ISlide14
3D Data Cube
H2[Fe III]He IBrγ-100km/s100km/sSlide15
Column Density Ratio (CDR) Diagrams
IRAS1-Center1300KSlide16
Column Density Ratio (CDR) Diagrams
IRAS1-SE11300KSlide17
Column Density Ratio (CDR) Diagrams
IRAS1-SE21300KSlide18
Column Density Ratio (CDR) Diagrams
IRAS1-SE31300KSlide19
Column Density Ratio (CDR) Diagrams
IRAS1-SE41300KSlide20
Column Density Ratio (CDR) Diagrams
IRAS1-SE51300KSlide21
Conclusion and Future WorkIGRINS spectra clearly show emissions both from ionized and neutral gases.
Position-Velocity diagrams of ionized gases indicate that they flow along the cavity walls (Δv = 39.906±2.203 km/s).No obvious motion (Δv = 10.026±0.134 km/s) is present in the H2 emission lines, indicating that there is little or no entrainment of the molecular gas by the ionized gas flow. => need to be confirmed with the complete map!Slide22
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