Near-infrared observations of two far-infrared sources in the W3 region - G133.8+1.4 /W3N/ and G133.982+1.14 /BS4/

AbstractInfrared observations of the galactic nucleus and conclusions regarding the nature of the objects present there are reviewed. Observations of three sources of infrared radiation are discussed: near-infrared emission from cool stars, mid- and far-infrared emission from dust, and line emission from ionized gas. These observations provide information about the mass distribution, the stellar population, and the origin and ionization of the compact mid-infrared sources. The possibility of the existence of a massive central black hole is discussed.

Download Full-text

Accretion and Outflow Activity in the Earliest Phases of Star-Formation: CO, Sub-mm Continuum, and Near-Infrared Observations

International Astronomical Union Colloquium ◽

10.1017/s0252921100043645 ◽

1997 ◽

Vol 163 ◽

pp. 725-726

Author(s):

K.-W. Hodapp ◽

E. F. Ladd

Keyword(s):

Near Infrared ◽

Spectral Energy Distribution ◽

Far Infrared ◽

Point Sources ◽

Spectral Energy ◽

Infrared Observations ◽

Circumstellar Material ◽

Dense Cores ◽

Wavelength Radiation ◽

Main Component

Stars in the earliest phases of their formation, i.e., those accreting the main component of their final mass, are deeply embedded within dense cores of dust and molecular material. Because of the high line-of-sight extinction and the large amount of circumstellar material, stellar emission is reprocessed by dust into long wavelength radiation, typically in the far-infrared and sub-millimeter bands. Consequently, the youngest sources are strong submillimeter continuum sources, and often undetectable as point sources in the near-infrared and optical. The most deeply embedded of these sources have been labelled “Class 0” sources by André, Ward-Thompson, & Barsony (1994), in an extension of the spectral energy distribution classification scheme first proposed by Adams, Lada, & Shu (1987).

Download Full-text

Near-infrared observations of the far-infrared source V region in NGC 6334

The Astrophysical Journal ◽

10.1086/160064 ◽

1982 ◽

Vol 258 ◽

pp. 165 ◽

Cited By ~ 13

Author(s):

J. Fischer ◽

R. R. Joyce ◽

M. Simon ◽

T. Simon

Keyword(s):

Near Infrared ◽

Far Infrared ◽

Infrared Source ◽

Infrared Observations ◽

V Region ◽

Ngc 6334

Download Full-text

The properties of far-infrared luminous galaxies. I Spectroscopic and near-infrared observations

The Astrophysical Journal ◽

10.1086/163423 ◽

1985 ◽

Vol 296 ◽

pp. 106 ◽

Cited By ~ 11

Author(s):

R. Elston ◽

M. E. Cornell ◽

M. J. Lebofsky

Keyword(s):

Near Infrared ◽

Far Infrared ◽

Infrared Observations ◽

Luminous Galaxies

Download Full-text

Near Infrared Spectroscopy and the Search for CO Emission in 3 Extremely Luminous IRAS Sources

Symposium - International Astronomical Union ◽

10.1017/s0074180900113014 ◽

1999 ◽

Vol 186 ◽

pp. 354-354

Author(s):

Aaron S. Evans ◽

D.B. Sanders ◽

Roc M. Cutri ◽

Simon J.E. Radford ◽

Phil M. Solomon ◽

...

Keyword(s):

Emission Line ◽

Rest Frame ◽

Near Infrared ◽

Extreme Values ◽

Far Infrared ◽

Molecular Gas ◽

Infrared Galaxies ◽

Upper Limits ◽

Infrared Sources ◽

Co Emission

Rest-frame 0.48–1.1 μm emission line strengths and molecular gas mass (H2) upper limits for three luminous infrared sources – the hyperluminous infrared galaxies (HyLIGs: Lir ≥ 1013L⊙ where Lir ~ L(8 – 1000μm) IRAS F09105+4108 (z = 0.4417), IRAS F15307+3252 (z = 0.926), and the optically-selected QSO PG 1634+706 (z = 1.338) - are presented. Diagnostic emission-line ratios ([O III] λ5007/Hβ, [S II] λ6724/Hα, [N II] λ6583/Hα, and [S III] λλ9069+9532/Hα) indicate a Seyfert 2-like spectrum for both infrared galaxies, consistent with previously published work. Upper limits on the molecular gas mass for all three sources are M(H2) < 1 - 3 × 1010h−2M⊙ (q0 = 0.5, H0 = 100h km s−1 Mpc−1), less than the H2 mass of the most gas-rich infrared galaxies in the local Universe. All three sources have Lir/L′CO ~ 1300 – 2000, the most extreme values for extragalactic sources measured to date. Given the relatively warm far-infrared colors for all three objects, much of their infrared luminosity may emanate from a relatively small quantity of hot dust near an AGN.

Download Full-text

Infrared observations of GGD objects

Symposium - International Astronomical Union ◽

10.1017/s0074180900156190 ◽

1987 ◽

Vol 122 ◽

pp. 125-126

Author(s):

R. Carballo ◽

C. Eiroa ◽

A. Mampaso

Keyword(s):

Main Sequence ◽

Near Infrared ◽

Far Infrared ◽

Infrared Emission ◽

Be Stars ◽

Main Sequence Stars ◽

Infrared Excess ◽

Dark Clouds ◽

Infrared Sources ◽

Different Characteristics

We present accurate positions and near infrared photometry (Table I) of 11 point-like objects in the neighbourhood of GGD objects obtained on the 1.55 m and on the 1.23 m in Teide Obs. and Calar Alto Obs. respectively, in Spain. Several of the near infrared sources are directly associated with the GGD nebulae and/or are candidate for their excitation. In addition some of them seem to be the near infrared counterparts of IRAS sources. We believe, on the basis of their infrared excess, far infrared emission (IRAS), association with nebulosity, coincidence with H2O masers or the fact that in most cases the observed luminosities are higher than those expected for main sequence stars, that most of them (9/12) are young stars embedded in the dark clouds which contain the GGD objects. The loci of the detected sources in an (H-K,K-L) infrared two-colour diagram is the same as that obtained for known pre-main sequence stars, such as T Tauris and Herbig Ae-Be stars, indicating the presence of dust shells with temperatures in the range 800–1500 K. The observed range in luminosity, 10–4600 L⊙, added to other different characteristics found between them, such' as the presence, or absence, of H2O masers, indicates the interest for a detailed study of the infrared sources and related GGD nebulae.

Download Full-text

IRTS: Infrared Telescope in Space

International Astronomical Union Colloquium ◽

10.1017/s0252921100077058 ◽

1990 ◽

Vol 123 ◽

pp. 215-222

Author(s):

Toshio Matsumoto

Keyword(s):

Focal Plane ◽

Near Infrared ◽

Space Shuttle ◽

Spectroscopic Measurement ◽

Small Space ◽

Valuable Data ◽

Infrared Telescope ◽

Wide Wavelength Range ◽

Infrared Sources ◽

Very High

AbstractIRTS is a small cryogenically cooled telescope onboard the small space platform SFU (Space Flyer Unit). SFU will be launched with the new Japanese HII rocket on January 1994 and retrieved by the space shuttle.The IRTS telescope has an aperture of only 15 cm diameter, but is optimized to observe diffuse extended infrared sources. Four focal plane instruments are being developed under collaboration between Japan and the U.S.A. IRTS covers a wide wavelength range from near-infrared to submillimeter region, and has a capability for the spectroscopic measurement. Due to newly developed detectors, the sky will be surveyed with very high sensitivities. IRTS will provide valuable data on cosmology, galactic structure, cosmic dust, etc.

Download Full-text

Comparison of satellite microwave backscattering (ASCAT) and visible/near-infrared reflectances (PARASOL) for the estimation of aeolian aerodynamic roughness length in arid and semi-arid regions

Atmospheric Measurement Techniques Discussions ◽

10.5194/amtd-5-2933-2012 ◽

2012 ◽

Vol 5 (2) ◽

pp. 2933-2957

Author(s):

C. Prigent ◽

C. Jiménez ◽

J. Catherinot

Keyword(s):

Arid Regions ◽

Near Infrared ◽

Roughness Length ◽

Aerodynamic Roughness Length ◽

Sources Of Information ◽

Transport Models ◽

Dust Transport ◽

Infrared Observations ◽

Aerodynamic Roughness ◽

Semi Arid

Abstract. Previous studies examined the possibility to estimate the aeolian aerodynamic roughness length from satellites, either from visible/near-infrared observations or from microwave backscattering measurements. Here we compare the potential of the two approaches and propose to merge the two sources of information to benefit from their complementary aspects, i.e. the high spatial resolution of the visible/near-infrared (PARASOL part of the A-Train) and the independence from atmospheric contamination of the active microwaves (ASCAT on board MetOp). A global map of the aeolian aerodynamic roughness length at 6 km resolution is derived, for arid and semi-arid regions. It shows very good consistency with the existing information on the properties of these surfaces. The dataset is available to the community, for use in atmospheric dust transport models.

Download Full-text