scholarly journals Infrared [Fe II] and Dust Emissions from Supernova Remnants

2013 ◽  
Vol 9 (S296) ◽  
pp. 214-221 ◽  
Author(s):  
Bon-Chul Koo
Keyword(s):  
Molecular Clouds ◽  
Supernova Remnants ◽  
Near Infrared ◽  
Dust Emission ◽  
Far Infrared ◽  
Atomic Gases ◽  
Core Collapse ◽  
Hot Plasma ◽  
Near Infrared Spectra ◽  
Thermal Emitters

AbstractSupernova remnants (SNRs) are strong thermal emitters of infrared radiation. The most prominent lines in the near-infrared spectra of SNRs are [Fe II] lines. The [Fe II] lines are from shocked dense atomic gases, so they trace SNRs in dense environments. After briefly reviewing the physics of the [Fe II] emission in SNR shocks, I describe the observational results which show that there are two groups of SNRs bright in [Fe II] emission: middle-aged SNRs interacting with molecular clouds and young core-collapse SNRs in dense circumstellar medium. The SNRs belonging to the former group are also bright in near-infrared H2 emission, indicating that both atomic and molecular shocks are pervasive in these SNRs. The SNRs belonging to the latter group have relatively small radii in general, implying that most of them are likely the remnants of SN IIL/b or SN IIn that had strong mass loss before the explosion. I also comment on the “[Fe II]-H2 reversal” in SNRs and on using the [Fe II]-line luminosity as an indicator of the supernova (SN) rate in galaxies. In the mid- and far-infrared regimes, thermal dust emission is dominant. The dust in SNRs can be heated either by collisions with gas species in a hot plasma or by radiation from a shock front. I discuss the characteristics of the infrared morphology of the SNRs interacting with molecular clouds and their dust heating processes. Finally, I give a brief summary of the detection of SN dust and crystalline silicate dust in SNRs.

scholarly journals Investigations of dust heating in M81, M83 and NGC 2403 with Herschel and Spitzer

2011 ◽  
Vol 7 (S284) ◽  
pp. 97-100
Author(s):  
George J. Bendo ◽  
Keyword(s):  
Star Formation ◽  
Flux Density ◽  
Near Infrared ◽  
Dust Emission ◽  
Far Infrared ◽  
Spectral Energy ◽  
Star Forming ◽  
Star Forming Regions ◽  
Star Formation Activity ◽  
Density Ratios

AbstractWe use Herschel Space Observatory and Spitzer Space Telescope 70-500 μm data along with ground-based optical and near-infrared data to understand how dust heating in the nearby face-on spiral galaxies M81, M83, and NGC 2403 is affected by the starlight from all stars and by the radiation from star-forming regions. We find that 70/160 μm flux density ratios tend to be more strongly influenced by star-forming regions. However, the 250/350 and 350/500 μm micron flux density ratios are more strongly affected by the light from the total stellar populations, suggesting that the dust emission at > 250 μm originates predominantly from a component that is colder than the dust seen at <160 μm and that is relatively unaffected by star formation activity. We conclude by discussing the implications of this for modelling the spectral energy distributions of both nearby and more distant galaxies and for using far-infrared dust emission to trace star formation.

scholarly journals Low Frequency Cutoffs in the Spectra of Radioquiet Quasars

1987 ◽  
Vol 121 ◽  
pp. 135-139
Author(s):  
R. Antonucci ◽  
R. Barvainis
Keyword(s):  
High Frequency ◽  
Near Infrared ◽  
Dust Emission ◽  
Low Frequency ◽  
Far Infrared ◽  
Low Energy Electrons ◽  
Order Of Magnitude ◽  
Infrared Continuum ◽  
Lower Cutoff ◽  
Rule Out

Radio-quiet and normal radio-loud quasars have very similar spectral properties in the ultraviolet, optical and near infrared regions, but their radio powers differ by several orders of magnitude. Somewhere between the near infrared and the radio their spectra must diverge dramatically.The IRAS survey detected 17 radio quiet quasars and luminous Seyfert 1's with −29. 5 ≤ Mv ≤ −21.6 (for Ho = 75). By coadding the survey data and using pointed observations, we have detections of most of these objects in all four IRAS passbands. The spectra are all rising with wavelength all the way to 100μ. We are measuring fluxes in the centimeter, millimeter, and, together with R Cutri, the near infrared and optical regions for each of these objects. Our goal is to constrain the location, shape, and spectral context of the low frequency cutoffs. Here we present the IRAS, millimeter and centimeter data. Measurements at the other wavelengths are still in progress.Although the spectra are rising steeply between 60μ and 100μ, we find that all of our objects are undetectable at 1.3 mm with the NRAO 12-m telescope. Our limits are typically an order of magnitude below the 100μ fluxes. (Ennis et al (1982) and Robson et al (1985) have already shown that the 1 mm fluxes of some radio quiet quasars must be below the extrapolation of the near infrared continuum.) Our objects are all extremely weak or undetected with the VLA at 2 cm and 1.3 cm, at levels typically three orders of magnitude below the 100μ fluxes. The sharpness of the required cutoffs allows us to rule out the hypothesis that the infrared is synchrotron radiation with the cutoff due to an absence of low energy electrons. The high frequency of the cutoffs makes free-free absorption implausible, but not impossible. It is possible that synchrotron self-absorption is suppressing the radio. There is circumstantial evidence that the far infrared is thermal dust emission. This would require a lower cutoff in the distribution of dust temperatures, which we think we can explain.

Non-Destructive Spectroscopic Investigations on Paintings Using Optical Fibers

1992 ◽  
Vol 267 ◽  
Author(s):  
M. Bacci ◽  
S. Baronti ◽  
A. Casini ◽  
F. Lotti ◽  
M. Picollo ◽  
...  
Keyword(s):  
Optical Fibers ◽  
Near Infrared ◽  
Far Infrared ◽  
Infrared Region ◽  
Infrared Range ◽  
Color Analysis ◽  
Near Infrared Spectra ◽  
Renaissance Period ◽  
Band Pass ◽  
Non Destructive

ABSTRACTThe main objective of our research is the development of totally non-destructive methodologies for the investigation of art works. We propose the use of fiber optic reflectance spectroscopy (FORS) in the visible and near-infrared region as a tool for the identification of the pigments used in painting. We have considered several representative inorganic artists' pigments (mainly till the Renaissance period); powder X-ray diffractograms and diffuse reflectance spectra in the visible, near-, middle- and far-infrared range were recorded for pure pigments. Then we prepared suitable samples with the same pigments using fresco, tempera and oil techniques. The visible and near-infrared spectra of these samples were recorded using an optical fiber spectrum analyzer; color analysis (chromaticity, dominant wavelength and purity) was also performed. The obtained results were used in the interpretation of the spectra obtained from some paintings collected in the Uffizi Gallery, Florence (Giotto and Luca Signorelli). The pointwise information obtained by FORS analysis was also used to calibrate and tune an image spectroscopy system, based on sequences of band-pass filtered images in the near infrared range.

Detection of CO and Dust Emission in Near-Infrared Spectra of SN 1998S

2000 ◽  
Vol 119 (6) ◽  
pp. 2968-2981 ◽  
Author(s):  
Christopher L. Gerardy ◽  
Robert A. Fesen ◽  
Peter Höflich ◽  
J. Craig Wheeler
Keyword(s):  
Infrared Spectra ◽  
Near Infrared ◽  
Dust Emission ◽  
Near Infrared Spectra

scholarly journals Dark Supernova Remnants Revealed by CO-Line Bubbles in the W43 Molecular Complex along the 4-kpc Galactic Arm

Galaxies ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 13
Author(s):  
Yoshiaki Sofue
Keyword(s):  
Molecular Clouds ◽  
Supernova Remnants ◽  
Dust Emission ◽  
Radio Continuum ◽  
Young Stellar Objects ◽  
Continuum Emission ◽  
Giant Molecular Clouds ◽  
Turbulent Structures ◽  
Stellar Objects ◽  
Receiver System

Fine structure of the density distribution in giant molecular clouds (GMCs) around W43 (G31+00+90 km s−1at ∼5.5 kpc) was analyzed using the FUGIN* CO-line survey at high-angular (20”∼0.5 pc) and velocity (1.3 km s−1) resolutions (*Four-receiver-system Unbiased Galactic Imaging survey with the Nobeyama 45-m telescope). The GMCs show highly turbulent structures, and the eddies are found to exhibit spherical bubble morphology appearing in narrow ranges of velocity channels. The bubbles are dark in radio continuum emission, unlike usual supernova remnants (SNR) or HII regions, and in infrared dust emission, unlike molecular bubbles around young stellar objects. The CO bubbles are interpreted as due to fully evolved buried SNRs in molecular clouds after rapid exhaustion of the released energy in dense molecular clouds. Then, the CO bubbles may be a direct evidence for exciting and maintaining the turbulence in GMCs by SN origin. Search for CO bubbles as “dark SNRs” (dSNR) will have implication to estimate the supernova rate more accurately, and hence the star formation activity in the Milky Way.

The motion and distribution of the gas in the central 300 pc of the galaxy as revealed by spectra of H 3 +

2019 ◽  
Vol 377 (2154) ◽  
pp. 20180400 ◽  
Author(s):  
T. R. Geballe ◽  
T. Oka ◽  
M. Goto
Keyword(s):  
Molecular Clouds ◽  
Large Fraction ◽  
Molecular Ions ◽  
Core Collapse ◽  
Supermassive Black Hole ◽  
Hot Plasma ◽  
The Galaxy ◽  
Sgr A ◽  
Past Activity ◽  
Unknown Component

Spectroscopy of absorption lines of H 3 + in the central molecular zone (CMZ) of the Galaxy show that a previously largely unknown component of the interstellar medium there, warm ( T ∼200 K) and diffuse ( n  ≲ 10 2  cm −3 ) gas, makes up a large fraction of the volume of the CMZ, and that this gas is moving radially outward from the centre. These discoveries upend the generally accepted understanding that the interstellar environment of the CMZ comprises almost entirely an ultra-hot plasma and dense molecular clouds. The radial momentum associated with the diffuse gas in the CMZ exceeds that of the ejecta of thousands of core-collapse supernovae and implies some extraordinary past activity in the centre, possibly associated with the supermassive black hole, Sgr A*. We speculate that within approximately 10 6 years, gravity could halt the expansion of the diffuse gas and that contraction towards the centre could then commence. This article is part of a discussion meeting issue ‘Advances in hydrogen molecular ions: H 3 + , H 5 + and beyond’.

scholarly journals Infrared Emission from AGN

1999 ◽  
Vol 194 ◽  
pp. 25-38
Author(s):  
D. B. Sanders
Keyword(s):  
Near Infrared ◽  
High Redshift ◽  
Dust Emission ◽  
Far Infrared ◽  
Infrared Emission ◽  
Substantial Fraction ◽  
Bolometric Luminosity ◽  
Submillimeter Wavelengths ◽  
Infrared Background ◽  
X Ray Background

Infrared observations of complete samples of active galactic nuclei (AGN) have shown that a substantial fraction of their bolometric luminosity is emitted at wavelengths ˜8–1000μm. In radio-loud and Blazar-like objects much of this emission appears to be direct non-thermal synchrotron radiation. However, in the much larger numbers of radio-quiet AGN it is now clear that thermal dust emission is responsible for the bulk of radiation from the near-infrared through submillimeter wavelengths. Luminous infrared-selected AGN are often surrounded by powerful nuclear starbursts, both of which appear to be fueled by enormous supplies of molecular gas and dust funneled into the nuclear region during the strong interaction/merger of gas rich disks. All-sky surveys in the infrared show that luminous infrared AGN are at least as numerous as optically-selected AGN of comparable bolometric luminosity, suggesting that AGN may spend a substantial fraction of their lifetime in a dust-enshrouded phase. The space density of luminous infrared AGN at high redshift may be sufficient to account for much of the X-Ray background, and for a substantial fraction of the far-infrared background as well. These objects plausibly represent a major epoch in the formation of spheroids and massive black holes (MBH).

scholarly journals Infrared Extragalactic Background Light

1990 ◽  
Vol 139 ◽  
pp. 317-326
Author(s):  
Toshio Matsumoto
Keyword(s):  
Near Infrared ◽  
Background Radiation ◽  
High Redshift ◽  
Dust Emission ◽  
Far Infrared ◽  
Cosmic Background Radiation ◽  
Infrared Region ◽  
Clear Correlation ◽  
Extragalactic Background Light ◽  
Background Light

Infrared extragalactic background light plays an important role in the study of the early history of the universe, especially as a probe to search for the primeval galaxies. In the near-infrared region, UV and visible light emitted from high redshift galaxies could be observable. Measurement of the sky fluctuation at 2.2 μm gives a very low upper limit. The rocket observation of the near-infrared diffuse emission reveals isotropic emission which is possibly ascribed to an extragalactic origin. The observed brightness and fluctuation are not consistent with the standard scenario of the primeval galaxies. In the far-infrared region, integrated light of dust emission of the distant galaxies forms another cosmic background radiation. IRAS and the Nagoya-Berkeley rocket experiment found a clear correlation between HI column density and far-infrared sky brightness; however, there remains an uncorrelated isotropic emission component. If we ascribe this emission to extragalactic origin, a fairly big evolution effect is required. In the submillimeter region, excess emission over the 2.74K blackbody spectrum was found, which requires the vast energy generation in the early universe.

Panchromatic Analysis for Nature of HIgh-z galaxies Tool (PANHIT)

2019 ◽  
Vol 15 (S341) ◽  
pp. 285-286
Author(s):  
Ken Mawatari ◽  
Akio K. Inoue ◽  
Satoshi Yamanaka ◽  
Takuya Hashimoto ◽  
Yoichi Tamura
Keyword(s):  
Physical Properties ◽  
Rest Frame ◽  
Near Infrared ◽  
Broad Band ◽  
Dust Emission ◽  
Far Infrared ◽  
Infrared Photometry ◽  
Spectral Emission ◽  
Line Flux ◽  
Faint Object

AbstractWe have developed a new SED fitting tool specialized for frontier redshift galaxies. It is a common case for high-z galaxies that the available data are restricted to rich optical to near-infrared photometry and few far-infrared (FIR) data deep enough to detect the faint object (e.g., HST/WFC3 + Spitzer/IRAC + ALMA). In such situation, one cannot perform a complicated modeling of dust emission in FIR regime. We then adopt simple treatment for the dust emission using empirical LIRG templates. Instead, we adopt a sophisticated and physically motivated modeling for stellar and nebular emission parts in rest-frame UV-to-optical regime. Our new code fits not only broad band photometry but also spectral emission line flux. There is an option to fit observed SED with two templates with different physical properties. Our new code, PANHIT, is now in public, and was already applied to some high-z frontier galaxies.

scholarly journals ALMA resolves molecular clouds in metal-poor Magellanic Bridge A

2020 ◽  
Vol 641 ◽  
pp. A97 ◽  
Author(s):  
M. T. Valdivia-Mena ◽  
M. Rubio ◽  
A. D. Bolatto ◽  
H. P. Saldaño ◽  
C. Verdugo
Keyword(s):  
Star Formation ◽  
Molecular Clouds ◽  
Dust Emission ◽  
Line Emission ◽  
Far Infrared ◽  
Continuum Emission ◽  
Molecular Gas ◽  
The North ◽  
Mass Conversion ◽  
North And South

Context. The Magellanic Bridge is a tidal feature located between the Magellanic Clouds, containing young stars formed in situ. Its proximity allows high-resolution studies of molecular gas, dust, and star formation in a tidal low-metallicity environment. Aims. Our goal is to characterize gas and dust emission in Magellanic Bridge A, the source with the highest 870 μm excess of emission found in single-dish surveys. Methods. Using the ALMA telescope including the Morita Array, we mapped a 3′ field of view centered on the Magellanic Bridge A molecular cloud, in 1.3 mm continuum emission and 12CO(2−1) line emission at subparsec resolution. This region was also mapped in continuum at 870 μm and in 12CO(2−1) line emission at ~6 pc resolution with the APEX telescope. To study its dust properties, we also use archival Herschel and Spitzer data. We combine the ALMA and APEX 12CO(2−1) line cubes to study the molecular gas emission. Results. Magellanic Bridge A breaks up into two distinct molecular clouds in dust and 12CO(2−1) emission, which we call North and South. Dust emission in the North source, according to our best parameters from fitting the far-infrared fluxes, is ≈3 K colder than in the South source in correspondence to its less developed star formation. Both dust sources present large submillimeter excesses in LABOCA data: according to our best fits the excess over the modified blackbody (MBB) fit to the Spitzer/Herschel continuum is E(870 μm) ~ 7 and E(870 μm) ~ 3 for the North and South sources, respectively. Nonetheless, we do not detect the corresponding 1.3 mm continuum with ALMA. Our limits are compatible with the extrapolation of the MBB fits, and therefore we cannot independently confirm the excess at this longer wavelength. The 12CO(2−1) emission is concentrated in two parsec-sized clouds with virial masses of around 400 and 700 M⊙. Their bulk volume densities are n(H2) ~ 0.7−2.6 × 103 cm−3, higher than typical bulk densities of Galactic molecular clouds. The 12CO luminosity to H2 mass conversion factor αCO is 6.5 and 15.3 M⊙ (K km s−1 pc2)−1 for the North and South clouds, calculated using their respective virial masses and 12CO(2−1) luminosities. Gas mass estimates from our MBB fits to dust emission yields masses M ~ 1.3 × 103 M⊙ and 2.9 × 103 M⊙ for North and South, respectively, a factor of ~4 higher than the virial masses we infer from 12CO.

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