scholarly journals Observations of Molecular Hydrogen in Shocks and PDRs with the Infrared Space Observatory

2000 ◽  
Vol 197 ◽  
pp. 177-190
Author(s):  
Christopher M. Wright
Keyword(s):  
Molecular Hydrogen ◽  
Gas Temperature ◽  
Space Observatory ◽  
Infrared Space Observatory ◽  
X Ray ◽  
Ss 433 ◽  
Isotopic Species ◽  
Galactic Source ◽  
First Time ◽  
Excitation Conditions

A review is presented of ISO observations of molecular hydrogen and its isotopic species, HD, toward various Galactic source types, such as shocks (Orion, DR 21, Cep A), photon dominated regions (IC 1396A, S140, Orion Bar) and putative X-ray excited sources (RCW 103, SS 433). In so doing I examine the similarities and differences in the H2 spectrum found under these different excitation conditions and mechanisms, and how the observations impact on some of the latest shock and PDR models. For instance, in addition to the ubiquitous ~ 2000 K component in shocks, seen using ground-based instrumentation, ISO reveals the existence of gas with both lower (150–800 K) and higher (≥ 3000 K) excitation temperatures. Further, ISO allows for the first time a measure of the bulk gas temperature toward PDRs (100–700 K), and H2 is also detected where X-ray emission is observed, providing at least circumstantial evidence of X-ray heating.

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 The Nature of Ultraluminous Infrared Galaxies

2001 ◽  
Vol 204 ◽  
pp. 179-191
Author(s):  
Eckhard Sturm
Keyword(s):  
Far Infrared ◽  
Spectroscopic Studies ◽  
Infrared Galaxies ◽  
Space Observatory ◽  
Infrared Space Observatory ◽  
Infrared Spectroscopic ◽  
Ultraluminous Infrared Galaxies ◽  
First Time

The Infrared Space Observatory (ISO) has for the first time made possible mid- and far-infrared spectroscopic studies of nearby and moderate redshift, dusty ultraluminous infrared galaxies (ULIRGs). We discuss recent SWS, LWS, ISOPHOT-S and ISOCAM (CVF) results on ULIRGs, addressing the following topics: What powers ULIRGs? What is the AGN-starburst connection? How do ULIRGs evolve? What is the connection of the local ULIRG population to the recently discovered population of mid-IR to submillimeter sources?

scholarly journals ISO spectroscopy of nearby starburst galaxies

1999 ◽  
Vol 193 ◽  
pp. 745-746 ◽  
Author(s):  
Dietmar Kunze ◽  
Dieter Lutz ◽  
Dimitra Rigopoulou ◽  
Michelle D. Thornley ◽  
Reinhard Genzel
Keyword(s):  
Wavelength Range ◽  
Short Wavelength ◽  
Molecular Hydrogen ◽  
Starburst Galaxies ◽  
Line Ratio ◽  
Emission Lines ◽  
Space Observatory ◽  
Infrared Space Observatory ◽  
Atomic Species

We present spectroscopic mid-IR observations of prominent starburst galaxies obtained with the Short Wavelength Spectrometer onboard the Infrared Space Observatory. The wavelength range accessible by ISO-SWS (2.5–45 μm) contains a large number of emission lines of atomic and molecular hydrogen and several other atomic species. In this paper we discuss the interpretation of the [Ne III] 15.5 μm/[Ne II] 12.8 μm line-ratio, the faint [OIV]25.9 μm line and the pure rotational lines of molecular hydrogen observed in our target galaxies.

scholarly journals Collimated radiation in SS 433

2019 ◽  
Vol 624 ◽  
pp. A127 ◽  
Author(s):  
Idel Waisberg ◽  
Jason Dexter ◽  
Pierre Olivier-Petrucci ◽  
Guillaume Dubus ◽  
Karine Perraut
Keyword(s):  
Spectral Synthesis ◽  
Spectral Energy Distribution ◽  
Compact Object ◽  
Spectral Energy ◽  
X Ray ◽  
Ss 433 ◽  
Heating Mechanism ◽  
Ionization Balance ◽  
First Time ◽  
Optical Bullets

Context. The microquasar SS 433 is well known for its precessing, relativistic, and highly collimated baryonic jets, which manifest in its optical spectrum as pairs of hydrogen and helium emission lines moving with large Doppler shifts. Depending on their heating mechanism, the optical jet bullets may serve as a probe of the collimated radiation coming from the inner region close to the compact object, and which is not directly visible to observers on Earth. Aims. We aim to better understand the baryonic jet phenomenon in SS 433, in particular the properties of the optical bullets and their interaction with the ionizing collimated radiation. Methods. The optical interferometer VLTI/GRAVITY has allowed us to spatially resolve the optical jets in SS 433 for the first time. We present here the second such observation taken over three nights in July 2017. In addition, we used the X-shooter spectrograph at VLT to study the optical bullets in SS 433 in detail. Over the full wavelength range 0.3−2.5 μm, we identified up to twenty pairs of jet lines observed simultaneously, which we modeled with the spectral synthesis code Cloudy. Results. GRAVITY reveals elongated exponential-like radial spatial profiles for the optical jets on scales ≲1−10 mas, suggestive of a heating mechanism acting throughout a long portion of the jet and naturally explained by photoionization by the collimated radiation. We also spatially resolve the movement of the optical bullets for the first time, detecting more extended jet components corresponding to previous ejections. Cloudy photoionization models can explain the spatial intensity profiles measured with GRAVITY and the emission line ratios from X-shooter, and constrain the properties of the optical bullets and the ionizing radiation. We find that the latter must peak in the UV with an isotropic luminosity (as inferred by a face-on observer) ∼1041 erg s−1. Provided that the X-ray spectral energy distribution is sufficiently hard, the collimated X-ray luminosity could still be high enough so that the face-on observer would see SS 433 as ultraluminous X-ray source and it would still be compatible with the H/He/He+ ionization balance of the optical bullets. The kinetic power in the optical jets is constrained to 2−20 × 1038 erg s−1, and the extinction in the optical jets to AV = 6.7 ± 0.1. We suggest there may be substantial AV ≳ 1 and structured circumstellar extinction in SS 433, likely arising from dust formed in equatorial outflows.

scholarly journals The Infrared Space Observatory (ISO): Overview and Status

1998 ◽  
Vol 11 (2) ◽  
pp. 1107-1109 ◽  
Author(s):  
M.F. Kessler
Keyword(s):  
Data Analysis ◽  
Industrial Development ◽  
Space Observatory ◽  
Infrared Space Observatory ◽  
Infrared Wavelengths ◽  
First Time ◽  
Helium Coolant

The Infrared Space Observatory (ISO) is a cryogenically-cooled satellite giving the astronomical community, for the first time, the capability of making detailed observations at infrared wavelengths (2.5-240 ˜m) with a sophisticated and sensitive set of observatory-class instruments for a period in excess of two years.The proposal for ISO was made to ESA in 1979 and it was selected in 1983 to be the next new start. The instruments were chosen in 1985 and ISO’s main industrial development started in 1988. Launch took place in November 1995 and the helium coolant is expected to last until April 1998. The calibration and data analysis will be improved during the post-operations phase, which is funded to the end of 2001.

scholarly journals Astromineralogy: Crystalline silicates

2003 ◽  
Vol 209 ◽  
pp. 291-298
Author(s):  
F. J. Molster
Keyword(s):  
Circumstellar Dust ◽  
Space Observatory ◽  
Infrared Space Observatory ◽  
Evolved Stars ◽  
Formation History ◽  
Long Time ◽  
Dust Component ◽  
The Many ◽  
Dust Distribution ◽  
First Time

Silicates are the most abundant dust component in our Universe. For a long time it was generally assumed that around evolved stars only amorphous silicates were present. The infrared space observatory (ISO; Kessler et al. 1996) discovered that the abundance of crystalline silicates can be quite significant. Thanks to ISO it is now for the first time possible to determine the exact chemical composition of the silicates, and in contrast to the amorphous silicates, the crystalline silicates turned out to be very Fe-poor (i.e. forsterite and enstatite). Careful investigations of the spectra of crystalline silicates in several conditions, both in laboratory and in space, have taken place. It was found that not only the abundance of the crystalline silicates is related to the spatial distribution of the circumstellar dust, but also the shape of the features differs between sources with and without a disk-like dust distribution. Because of the many spectral features of the crystalline silicates one can easily determine temperatures and mass ratios for enstatite and forsterite. But even single features contain interesting information. The position and FWHM of the 69.0 micron forsterite feature, might be used as a new diagnostic of characteristic temperatures of (crystalline) silicate dust, while the 33.6 micron forsterite feature bears evidence for its formation history.

Diphosphinoazine Rhodium(I) and Iridium(I) Complexes

2006 ◽  
Vol 71 (2) ◽  
pp. 197-206 ◽  
Author(s):  
Martin Pošta ◽  
Jan Čermák ◽  
Pavel Vojtíšek ◽  
Ivana Císařová
Keyword(s):  
Rhodium Complexes ◽  
Iridium Complexes ◽  
X Ray ◽  
First Time

The first rhodium complexes of diphosphinoazines [{RhCl(1,2-η:5,6-η-CH=CHCH2CH2CH=CHCH2CH2)}2 {μ-R2PCH2C(But)=NN=C(But)CH2PR2] (R = Ph, Cy, Pri) were prepared by cleavage of the bridge in chloro(cycloocta-1,5-diene)rhodium(I) dimer, the analogous iridium(I) complexes were also prepared for the first time. The X-ray structures of isostructural rhodium and iridium complexes with bis(dicyclohexylphosphino)pinacoloneazine were determined. Diphosphinoazine ligands in the complexes remained in (Z,Z) configuration bridging two RhCl(C8H12) units.

scholarly journals Molecules in the Magellanic Clouds

1991 ◽  
Vol 148 ◽  
pp. 415-420 ◽  
Author(s):  
R. S. Booth ◽  
Th. De Graauw
Keyword(s):  
High Resolution ◽  
Molecular Clouds ◽  
Short Review ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Magellanic Clouds ◽  
Giant Molecular Clouds ◽  
Interstellar Molecules ◽  
First Time ◽  
Excitation Conditions

In this short review we describe recent new observations of millimetre transitions of molecules in selected regions of the Magellanic Clouds. The observations were made using the Swedish-ESO Submillimetre Telescope, SEST, (Booth et al. 1989), the relatively high resolution of which facilitates, for the first time, observations of individual giant molecular clouds in the Magellanic Clouds. We have mapped the distribution of the emission from the two lowest rotational transitions of 12CO and 13CO and hence have derived excitation conditions for the molecule. In addition, we have observed several well-known interstellar molecules in the same regions, thus doubling the number of known molecules in the Large Magellanic Cloud (LMC). The fact that all the observations have been made under controlled conditions with the same telescope enables a reasonable intercomparison of the molecular column densities. In particular, we are able to observe the relative abundances among the different isotopically substituted species of CO.

scholarly journals Line observations of the 30-Dor complex and N159A5 with the MPE imaging NIR spectrometer FAST

1991 ◽  
Vol 148 ◽  
pp. 205-206 ◽  
Author(s):  
A. Krabbe ◽  
J. Storey ◽  
V. Rotaciuc ◽  
S. Drapatz ◽  
R. Genzel
Keyword(s):  
Spatial Resolution ◽  
Molecular Hydrogen ◽  
Near Infrared ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Emission Lines ◽  
Resolving Power ◽  
Max Planck ◽  
First Time ◽  
Infrared Array

Images with subarcsec spatial resolution in the light of near-infrared atomic (Bry) and molecular hydrogen H2 (S(1) v=1-0) emission lines were obtained for some extended, pointlike objects in the Large Magellanic Cloud (LMC) for the first time. We used the Max-Planck-Institut für extraterrestrische Physik (MPE) near-infrared array spectrometer FAST (image scale 0.8”/pix, spectral resolving power 950) at the ESO/MPI 2.2m telescope, La Silla. We present some results on the 30-Dor complex and N159A5.

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