The molecular hydrogen emission around L1551 IRS 5 - Shock-heated molecular gas at the base of the molecular outflow

1992 ◽  
Vol 387 ◽  
pp. L93 ◽  
Author(s):  
Takuya Yamashita ◽  
Motohide Tamura
Keyword(s):  
Molecular Hydrogen ◽  
Molecular Gas ◽  
Hydrogen Emission ◽  
Molecular Outflow

scholarly journals Molecular Hydrogen Emission in Embedded Flows

1997 ◽  
Vol 182 ◽  
pp. 93-102 ◽  
Author(s):  
Jochen Eislöffel
Keyword(s):  
Molecular Hydrogen ◽  
Jet Flow ◽  
Young Stars ◽  
Molecular Gas ◽  
Hydrogen Emission

This overview of recent observations of molecular hydrogen (H2) in outflows from young stars discusses the morphology, the excitation and the kinematics of the H2 gas in these flows. A comparison between the H2 and CO outflows will lead us to the conclusion that highly-collimated jets may drive the latter. We also discuss the mechanisms which can entrain ambient molecular gas into the jet flow.

The Kinematics and Excitation of Molecular Hydrogen Emission in the Planetary Nebula BD +30o3639

1998 ◽  
Vol 498 (1) ◽  
pp. 267-277 ◽  
Author(s):  
D. L. Shupe ◽  
J. E. Larkin ◽  
R. A. Knop ◽  
L. Armus ◽  
K. Matthews ◽  
...  
Keyword(s):  
Planetary Nebula ◽  
Molecular Hydrogen ◽  
Hydrogen Emission

scholarly journals AGN Spectra as Seen by the Infrared Space Observatory: First Results

1997 ◽  
Vol 159 ◽  
pp. 333-336
Author(s):  
D. Lutz ◽  
R. Genzel ◽  
E. Sturm ◽  
A.F.M. Moorwood ◽  
E. Oliva ◽  
...  
Keyword(s):  
Fine Structure ◽  
Short Wavelength ◽  
Molecular Hydrogen ◽  
Molecular Gas ◽  
Space Observatory ◽  
Infrared Space Observatory ◽  
First Results ◽  
External Galaxies ◽  
First Time ◽  
Fine Structure Lines

AbstractWe discuss 2.5–45 µm spectra of the Circinus galaxy and of Cen A, obtained with the Short Wavelength Spectrometer (SWS) on board the Infrared Space Observatory. The large number of detected ionic fine structure lines, observable also in visually obscured sources, provides strong constraints on the shape of the ionizing spectrum, which is found to exhibit a UV bump peaking at ~ 70 eV in the case of Circinus. Pure rotational emission of molecular hydrogen, directly probing warm molecular gas, can for the first time be detected in external galaxies.

scholarly journals Hidden molecular outflow in the LIRG Zw 049.057

2018 ◽  
Vol 609 ◽  
pp. A75 ◽  
Author(s):  
N. Falstad ◽  
S. Aalto ◽  
J. G. Mangum ◽  
F. Costagliola ◽  
J. S. Gallagher ◽  
...  
Keyword(s):  
Far Infrared ◽  
Minor Axis ◽  
Spectral Lines ◽  
Continuum Emission ◽  
High Angular Resolution ◽  
Molecular Gas ◽  
Nuclear Activity ◽  
Molecular Outflow ◽  
The Galaxy ◽  
Excitation Conditions

Context. Feedback in the form of mass outflows driven by star formation or active galactic nuclei is a key component of galaxy evolution. The luminous infrared galaxy Zw 049.057 harbours a compact obscured nucleus with a possible far-infrared signature of outflowing molecular gas. Due to the high optical depths at far-infrared wavelengths, however, the interpretation of the outflow signature is uncertain. At millimeter and radio wavelengths, the radiation is better able to penetrate the large columns of gas and dust responsible for the obscuration. Aims. We aim to investigate the molecular gas distribution and kinematics in the nucleus of Zw 049.057 in order to confirm and locate the molecular outflow, with the ultimate goal to understand how the nuclear activity affects the host galaxy. Methods. We used high angular resolution observations from the Submillimeter Array (SMA), the Atacama Large Millimeter/submillimeter Array (ALMA), and the Karl G. Jansky Very Large Array (VLA) to image the CO J = 2–1 and J = 6–5 emission, the 690 GHz continuum, the radio centimeter continuum, and absorptions by rotationally excited OH. Results. The CO line profiles exhibit wings extending ~ 300 km s-1 beyond the systemic velocity. At centimeter wavelengths, we find a compact (~ 40 pc) continuum component in the nucleus, with weaker emission extending several 100 pc approximately along the major and minor axes of the galaxy. In the OH absorption lines toward the compact continuum, wings extending to a similar velocity as for the CO are only seen on the blue side of the profile. The weak centimeter continuum emission along the minor axis is aligned with a highly collimated, jet-like dust feature previously seen in near-infrared images of the galaxy. Comparison of the apparent optical depths in the OH lines indicate that the excitation conditions in Zw 049.057 differ from those within other OH megamaser galaxies. Conclusions. We interpret the wings in the spectral lines as signatures of a nuclear molecular outflow. A relation between this outflow and the minor axis radio feature is possible, although further studies are required to investigate this possible association and understand the connection between the outflow and the nuclear activity. Finally, we suggest that the differing OH excitation conditions are further evidence that Zw 049.057 is in a transition phase between megamaser and kilomaser activity.

scholarly journals The Connection between Molecular Gas and Star Formation in XUV Disks

2016 ◽  
Vol 11 (S321) ◽  
pp. 214-216
Author(s):  
Linda C. Watson
Keyword(s):  
Star Formation ◽  
Molecular Hydrogen ◽  
Optical Disk ◽  
Molecular Gas ◽  
Star Forming ◽  
Star Forming Regions

AbstractWe found that star-forming regions in extended ultraviolet (XUV) disks are generally consistent with the molecular-hydrogen Kennicutt-Schmidt law that applies within the inner, optical disk. This is true for star formation rates based on Hα + 24 μm data or FUV + 24 μm data. We estimated that the star-forming regions have ages of 1 − 7 Myr and propose that the presence or absence of molecular gas provides an additional “clock” that may help distinguish between aging and stochasticity as the explanation for the low Hα-to-FUV flux ratios in XUV disks. This contribution is a summary of the work originally presented in Watson et al. (2016).

scholarly journals Shocked Molecular Hydrogen from Star Forming Regions

1987 ◽  
Vol 115 ◽  
pp. 181-181 ◽  
Author(s):  
Adair P. Lane ◽  
John Bally
Keyword(s):  
Shock Waves ◽  
High Velocity ◽  
Molecular Hydrogen ◽  
Near Infrared ◽  
Young Stars ◽  
Emission Lines ◽  
Molecular Gas ◽  
Star Forming ◽  
Star Forming Regions ◽  
Post Shock

Near infrared (2 micron) emission lines from molecular hydrogen provide a powerful probe of the morphology and energetics of outflows associated with stellar birth. The H2 emission regions trace the location of shock waves formed when the high velocity outflow from young stars encounters dense quiescent gas. Since H2 is the dominant coolant of the hot post-shock molecular gas, the H2 lines provide a measure of the fraction of the total mechanical luminosity radiated away from the cloud.

scholarly journals Conversion of HI Molecule to H2 Molecule

2015 ◽  
Vol 5 ◽  
pp. 82-86
Author(s):  
Arjun Kumar Gautam
Keyword(s):  
Historical Development ◽  
Molecular Hydrogen ◽  
Interstellar Dust ◽  
Formation Rate ◽  
Theoretical Models ◽  
Molecular Gas ◽  
Astronomical Data ◽  
Interstellar Dust Grains ◽  
H2 Formation ◽  
H2 Molecule

In this article I review the historical development and conversion of atomic to molecular hydrogen in astronomy. I discuss how the discoveries of HI and H2 in the interstellar medium were followed by studies of the relative abundance of atomic and molecular gas. Understanding this led to increasingly sophisticated theoretical models for H2 formation on the surface of interstellar dust grains. In certain situations, astronomical data can be used to constrain the formation rate of H2 molecules. Finally, I use the reasonably well-determined chemistry of HI and H2 to determine the overall timescale of star formation. The Himalayan Physics Vol. 5, No. 5, Nov. 2014 Page: 82-86

scholarly journals Massive Molecular Outflow and 100 kpc Extended Cold Halo Gas in the Enormous Lyα Nebula of QSO 1228+3128

2021 ◽  
Vol 922 (2) ◽  
pp. L29
Author(s):  
Jianrui Li ◽  
Bjorn H. C. Emonts ◽  
Zheng Cai ◽  
J. Xavier Prochaska ◽  
Ilsang Yoon ◽  
...  
Keyword(s):  
Radio Source ◽  
Bulk Velocity ◽  
Molecular Gas ◽  
Gas Reservoir ◽  
Massive Galaxies ◽  
Gas Phases ◽  
Molecular Outflow ◽  
Halo Gas ◽  
Massive Outflow ◽  
Co Emission

Abstract The link between the circumgalactic medium (CGM) and the stellar growth of massive galaxies at high-z depends on the properties of the widespread cold molecular gas. As part of the SUPERCOLD-CGM survey (Survey of Protocluster ELANe Revealing CO/[C i] in the Lyα-Detected CGM), we present the radio-loud QSO Q1228+3128 at z = 2.2218, which is embedded in an enormous Lyα nebula. ALMA+ACA observations of CO(4–3) reveal both a massive molecular outflow, and a more extended molecular gas reservoir across ∼100 kpc in the CGM, each containing a mass of M H2 ∼ 4–5 × 1010 M ⊙. The outflow and molecular CGM are aligned spatially, along the direction of an inner radio jet. After reanalysis of Lyα data of Q1228+3128 from the Keck Cosmic Web Imager, we found that the velocity of the extended CO agrees with the redshift derived from the Lyα nebula and the bulk velocity of the massive outflow. We propose a scenario where the radio source in Q1228+3128 is driving the molecular outflow and perhaps also enriching or cooling the CGM. In addition, we found that the extended CO emission is nearly perpendicular to the extended Lyα nebula spatially, indicating that the two gas phases are not well mixed, and possibly even represent different phenomena (e.g., outflow versus infall). Our results provide crucial evidence in support of predicted baryonic recycling processes that drive the early evolution of massive galaxies.

scholarly journals The Molecular Outflow and CO Bullets in HH111

1997 ◽  
Vol 182 ◽  
pp. 141-152 ◽  
Author(s):  
J. Cernicharo ◽  
R. Neri ◽  
Bo Reipurth
Keyword(s):  
High Velocity ◽  
Angular Resolution ◽  
High Angular Resolution ◽  
Molecular Gas ◽  
Kinetic Temperature ◽  
Low Velocity ◽  
Molecular Outflow ◽  
Hh Objects ◽  
Physical Phenomena ◽  
First Time

We present high angular resolution observations of the molecular outflow associated with the optical jet and HH objects of the HH111 system. Interferometric observations in the CO J =2–1 and J =1–0 lines of the high velocity bullets associated with HH111 are presented for the first time. The molecular gas in these high velocity clumps has a moderate kinetic temperature and a mass of a few 10–4 M⊙ per bullet. We favor the view that HH jets and CO bullets, which represent different manifestations of the same physical phenomena, are driving the low-velocity molecular outflow.

scholarly journals ULTRALUMINOUS STAR-FORMING GALAXIES AND EXTREMELY LUMINOUS WARM MOLECULAR HYDROGEN EMISSION ATz= 2.16 IN THE PKS 1138–26 RADIO GALAXY PROTOCLUSTER

2012 ◽  
Vol 751 (1) ◽  
pp. 13 ◽  
Author(s):  
P. Ogle ◽  
J. E. Davies ◽  
P. N. Appleton ◽  
B. Bertincourt ◽  
N. Seymour ◽  
...  
Keyword(s):  
Molecular Hydrogen ◽  
Radio Galaxy ◽  
Star Forming ◽  
Hydrogen Emission
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