scholarly journals Deep Near‐Infrared Observations of L1014: Revealing the Nature of the Core and Its Embedded Source

2006 ◽  
Vol 640 (1) ◽  
pp. 391-401 ◽  
Author(s):  
Tracy L. Huard ◽  
Philip C. Myers ◽  
David C. Murphy ◽  
Lionel J. Crews ◽  
Charles J. Lada ◽  
...  
Keyword(s):  
Near Infrared ◽  
Infrared Observations ◽  
The Core

scholarly journals Optical and near-infrared observations of the SPT2349-56 proto-cluster core at z = 4.3

2021 ◽  
Vol 502 (2) ◽  
pp. 1797-1815
Author(s):  
K M Rotermund ◽  
S C Chapman ◽  
K A Phadke ◽  
R Hill ◽  
E Pass ◽  
...  
Keyword(s):  
Near Infrared ◽  
Early Stage ◽  
Stellar Mass ◽  
Cluster Core ◽  
Cluster Galaxy ◽  
Infrared Observations ◽  
The Core ◽  
Virial Mass ◽  
Stellar Masses ◽  
Optical Surveys

ABSTRACT We present Gemini-S and Spitzer-IRAC optical-through-near-IR observations in the field of the SPT2349-56 proto-cluster at z = 4.3. We detect optical/IR counterparts for only 9 of the 14 submillimetre galaxies (SMGs) previously identified by ALMA in the core of SPT2349-56. In addition, we detect four z ∼ 4 Lyman-break galaxies (LBGs) in the 30 arcsec-diameter region surrounding this proto-cluster core. Three of the four LBGs are new systems, while one appears to be a counterpart of one of the nine observed SMGs. We identify a candidate brightest cluster galaxy (BCG) with a stellar mass of $(3.2^{+2.3}_{-1.4})\times 10^{11}$ M⊙. The stellar masses of the eight other SMGs place them on, above, and below the main sequence of star formation at z ≈ 4.5. The cumulative stellar mass for the SPT2349-56 core is at least (12.2 ± 2.8) × 1011 M⊙, a sizeable fraction of the stellar mass in local BCGs, and close to the universal baryon fraction (0.19) relative to the virial mass of the core (1013 M⊙). As all 14 of these SMGs are destined to quickly merge, we conclude that the proto-cluster core has already developed a significant stellar mass at this early stage, comparable to z = 1 BCGs. Importantly, we also find that the SPT2349-56 core structure would be difficult to uncover in optical surveys, with none of the ALMA sources being easily identifiable or constrained through g, r, and i colour selection in deep optical surveys and only a modest overdensity of LBGs over the more extended structure. SPT2349-56 therefore represents a truly dust-obscured phase of a massive cluster core under formation.

Near-infrared observations of ionized hydrogen at the core of the Galaxy

1979 ◽  
Vol 229 ◽  
pp. 917 ◽  
Author(s):  
J. Bally ◽  
N. Z. Scoville ◽  
R. R. Joyce
Keyword(s):  
Near Infrared ◽  
Infrared Observations ◽  
The Core ◽  
The Galaxy

scholarly journals High-contrast and resolution near-infrared photometry of the core of R136

2021 ◽  
Vol 503 (1) ◽  
pp. 292-311
Author(s):  
Zeinab Khorrami ◽  
Maud Langlois ◽  
Paul C Clark ◽  
Farrokh Vakili ◽  
Anne S M Buckner ◽  
...  
Keyword(s):  
Adaptive Optics ◽  
Near Infrared ◽  
Outer Region ◽  
Mass Range ◽  
Mass Function ◽  
Large Magellanic Cloud ◽  
Star Forming ◽  
The Core ◽  
Very Large Telescope ◽  
30 Doradus

ABSTRACT We present the sharpest and deepest near-infrared photometric analysis of the core of R136, a newly formed massive star cluster at the centre of the 30 Doradus star-forming region in the Large Magellanic Cloud. We used the extreme adaptive optics of the SPHERE focal instrument implemented on the ESO Very Large Telescope and operated in its IRDIS imaging mode for the second time with longer exposure time in the H and K filters. Our aim was to (i) increase the number of resolved sources in the core of R136, and (ii) to compare with the first epoch to classify the properties of the detected common sources between the two epochs. Within the field of view (FOV) of 10.8″ × 12.1″ ($2.7\,\text {pc}\times 3.0\, \text {pc}$), we detected 1499 sources in both H and K filters, for which 76 per cent of these sources have visual companions closer than 0.2″. The larger number of detected sources enabled us to better sample the mass function (MF). The MF slopes are estimated at ages of 1, 1.5, and 2 Myr, at different radii, and for different mass ranges. The MF slopes for the mass range of 10–300 M⊙ are about 0.3 dex steeper than the mass range of 3–300 M⊙, for the whole FOV and different radii. Comparing the JHK colours of 790 sources common in between the two epochs, 67 per cent of detected sources in the outer region (r > 3″) are not consistent with evolutionary models at 1–2 Myr and with extinctions similar to the average cluster value, suggesting an origin from ongoing star formation within 30 Doradus, unrelated to R136.

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

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).

scholarly journals 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

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.

scholarly journals Near-infrared observations of the Fornax dwarf galaxy

2007 ◽  
Vol 467 (3) ◽  
pp. 1025-1036 ◽  
Author(s):  
M. Gullieuszik ◽  
E. V. Held ◽  
L. Rizzi ◽  
I. Saviane ◽  
Y. Momany ◽  
...  
Keyword(s):  
Near Infrared ◽  
Dwarf Galaxy ◽  
Infrared Observations

scholarly journals Secondary eclipses of WASP-18b – near-infrared observations with the Anglo-Australian Telescope, the Magellan Clay Telescope and the LCOGT network

2018 ◽  
Vol 483 (4) ◽  
pp. 5110-5122 ◽  
Author(s):  
L Kedziora-Chudczer ◽  
G Zhou ◽  
J Bailey ◽  
D D R Bayliss ◽  
C G Tinney ◽  
...  
Keyword(s):  
Near Infrared ◽  
Infrared Observations

Near-Infrared Observations of KH 15D through the 2003 February Eclipse

2004 ◽  
Vol 128 (6) ◽  
pp. 2977-2980 ◽  
Author(s):  
Roger Knacke ◽  
Sergio Fajardo-Acosta ◽  
A. T. Tokunaga
Keyword(s):  
Near Infrared ◽  
Infrared Observations

scholarly journals Exploring the inner parsecs of active galactic nuclei using near-infrared high resolution polarimetric simulations with MontAGN

2018 ◽  
Vol 612 ◽  
pp. A69 ◽  
Author(s):  
L. Grosset ◽  
D. Rouan ◽  
D. Gratadour ◽  
D. Pelat ◽  
J. Orkisz ◽  
...  
Keyword(s):  
Active Galactic Nuclei ◽  
Optical Depth ◽  
Near Infrared ◽  
Galactic Nuclei ◽  
Constant Density ◽  
Characteristic Model ◽  
Infrared Observations ◽  
Current Estimation ◽  
Direct Light ◽  
Ngc 1068

Aims. In this paper we aim to constrain the properties of dust structures in the central first parsecs of active galactic nuclei (AGN). Our goal is to study the required optical depth and composition of different dusty and ionised structures. Methods. We developed a radiative transfer code called Monte Carlo for Active Galactic Nuclei (MontAGN), which is optimised for polarimetric observations in the infrared. With both this code and STOKES, designed to be relevant from the hard X-ray band to near-infrared wavelengths, we investigate the polarisation emerging from a characteristic model of the AGN environment. For this purpose, we compare predictions of our models with previous infrared observations of NGC 1068, and try to reproduce several key polarisation patterns revealed by polarisation mapping. Results. We constrain the required dust structures and their densities. More precisely, we find that the electron density inside the ionisation cone is about 2.0 × 109 m−3. With structures constituted of spherical grains of constant density, we also highlight that the torus should be thicker than 20 in term of K-band optical depth to block direct light from the centre. It should also have a stratification in density: a less dense outer rim with an optical depth at 2.2 μm typically between 0.8 and 4 for observing the double scattering effect previously proposed. Conclusions. We bring constraints on the dust structures in the inner parsecs of an AGN model supposed to describe NGC 1068. When compared to observations, this leads to an optical depth of at least 20 in the Ks band for the torus of NGC 1068, corresponding to τV ≈ 170, which is within the range of current estimation based on observations. In the future, we will improve our study by including non-uniform dust structures and aligned elongated grains to constrain other possible interpretations of the observations.

scholarly journals Near-infrared observations of the Z about 2.3 IRAS source FSC 10214 + 4724

1991 ◽  
Vol 381 ◽  
pp. L55 ◽  
Author(s):  
B. T. Soifer ◽  
G. Neugebauer ◽  
J. R. Graham ◽  
K. Matthews ◽  
J. M. Mazzarella ◽  
...  
Keyword(s):  
Near Infrared ◽  
Iras Source ◽  
Infrared Observations
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