A New Symmetrical Far Infrared Nebula at -33° Declination

1970 ◽  
Vol 7 (7) ◽  
pp. 3-9
Author(s):  
B Aryal ◽  
K Simkhada ◽  
C Rajbahak ◽  
R Weinberger
Keyword(s):  
Flux Density ◽  
Region Of Interest ◽  
Far Infrared ◽  
Infrared Emission ◽  
Color Temperature ◽  
Ultraviolet Emission ◽  
Infrared Wavelength ◽  
Star Forming ◽  
Scientific World ◽  
Astronomical Satellite

A systematic search at far infrared wavelength in IRAS (Infrared Astronomical Satellite) survey using Groningen Server is performed and investigated a new symmetrical far-infrared (~3° x 2°) filamentary emission at R.A. (J2000) = 21h28m51s and Dec. (J2000) = -33°53'23''. The softwares ALADIN2.5 and ASTROLINUX5.0 are used for the data reduction. We have performed multiwavelength study in the region of interest. The physical properties, flux density, temperature and mass of the nebula are estimated and discussed. In the multiwavelength study, the optical and ultraviolet emission is found to be negligible. A significant far infrared emission is noticed. The radio and X-ray emission is observed to be moderate. It is found that there is a maxima in each filaments, that can clearly seen in 60 μm and 100 μm wavelengths. This indicates that the structure is nearby and a strong external force is influencing its shape. No star is forming in our region of interest. Our symmetrical far infrared nebula belongs to category II type cloud, appearing as diffuse emission of nearly faint optical surface brightness but showing a clumpy structure with no star forming. Total mass of the gas of our nebula is found to lie in the range 1.275 - 3.000 x 103 Msun. This estimation is based on the results of flux density study assuming a distance 150±50 pc and dust color temperature 25±5 K. Key Words: Interstellar Medium; Stars; Nebula; Infrared Emission. DOI: 10.3126/sw.v7i7.3815 Scientific World Vol.7(7) 2009 pp.3-9

scholarly journals A Study of a Cavity Nearby a Pulsar at -60º Latitude in the Far Infrared Map

2017 ◽  
Vol 4 (1) ◽  
pp. 33
Author(s):  
A. K. Jha ◽  
B. Aryal
Keyword(s):  
Flux Density ◽  
Region Of Interest ◽  
Far Infrared ◽  
Density Variation ◽  
Color Temperature ◽  
Dust Structure ◽  
The Past ◽  
Infrared Astronomical Satellite ◽  
Astronomical Satellite ◽  
Pulsar Evolution

<p>We present physical properties of a region in the interstellar medium where the past evolutionary remnant of pulsar evolution is observed. For this, a systematic search of dust structure in the far infrared (100 μm and 60 μm) IRAS (Infrared Astronomical Satellite) survey was performed using Sky View Observatory. Our selection criteria are as follows: (a) Cavity should be greater than 0.25 degree in diameter and (b) the cavity should have 3-fold minima in flux density. In the 100 micron infrared map, a new cavity-like isolated far infrared dust structure (size ~ 1.62 pc x 0.98 pc) is found at R.A. (J2000) 18h 33m 14.8s and Dec. (J2000) -60° 23' 24". We have studied flux density variation and temperature variation within the structure. We found that the dust color temperature varies from 22.78 K to 24.78 K, with offset of 2 K. The dust mass of each pixel of the region of interest was calculated using their dust color temperature. The excess mass in the region was found to be 1.62 x 10<sup>23</sup> Kg. The energy required to create that inhomogeneity in the structure is calculated to be 3.24 x10<sup>35</sup> J.</p><p><strong>Journal of Nepal Physical Society</strong><em><br /></em>Volume 4, Issue 1, February 2017, Page: 33-41</p>

scholarly journals Study of Dust Cavity around the White Dwarf WD 0352-049 in Infrared Astronomical Satellite Map

2021 ◽  
Vol 7 (2) ◽  
pp. 110-118
Author(s):  
M. S. Paudel ◽  
P. Bhandari ◽  
S. Bhattarai
Keyword(s):  
Flux Density ◽  
White Dwarf ◽  
Background Radiation ◽  
Three Dimensional ◽  
Far Infrared ◽  
Color Temperature ◽  
Cavity Structure ◽  
Dust Mass ◽  
Infrared Astronomical Satellite ◽  
Astronomical Satellite

In this work, we have studied the far-infrared images of the dust cavity around the White Dwarf WD 0352-049 available in Infrared Astronomical Satellite Map from Sky View Observatory. The size of the cavity is 24.48 pc × 8.10 pc. We have studied the relative infrared flux density and calculated the dust color temperature and dust mass. The temperature of the whole cavity structure lies between a maximum value 24.09 ± 0.50 K to a minimum 21.87 ± 0.61K with fluctuation of 2.22 K and an average value of 23.09 ± 1.11 K. The small fluctuation of dust color temperature suggests that the dust in cavity structure is evolving independently and less disturbed from background radiation sources. The color map shows the identical distribution of flux at 60 μm and 100 μm and the inverse distribution of dust color temperature and dust mass. There is a Gaussian-like distribution of relative flux density, dust color temperature and dust mass. The Gaussian distribution of temperature suggests that the dusts in cavity are in local thermodynamic equilibrium. The study of relative flux density and dust color temperature along the major and minor axis shows there is a sinusoidal fluctuation of flux and temperature, which might be due to the wind generated by White Dwarf located nearby the center of the cavity structure. The total dust mass of the dust is found to be 0.07 Mʘ and that of gas is 13.66 Mʘ. The Jeans mass of the structure is less than the total mass of gas in the structure, suggesting the possibility of star formation activity by gravitational collapse in the future. Also, the study of inclination angle suggests that the three-dimensional shape of the structure is uniform and regularly shaped.

scholarly journals Study of Far Infrared Nebula at Declination +53° (J2000) In Iras Map

2017 ◽  
pp. 76-79
Author(s):  
Sabin Gautam ◽  
Suman Gautam ◽  
Parashu Ram Poudel
Keyword(s):  
Total Mass ◽  
Far Infrared ◽  
Density Variation ◽  
Discrete Source ◽  
Color Temperature ◽  
Formation Mechanisms ◽  
Star Forming ◽  
Using Data ◽  
Astronomical Satellite ◽  
Right Ascension

In this present work we studied the flux density variation, calculate temperature, dust mass and finally Jean’s mass of structure using data reduction software ALADIN2.5. Our aim was to test whether this region is star forming or not. Sky view observatory was used for the search of isolated nebular structure in the far infrared (100 μm and 60 μm) in IRAS (Infrared Astronomical Satellite) catalogue. Stellarium software was used to find coordinate of the structure. A far infrared dust structure (about ~ 11.99 × 3.14 pc.) at Right Ascension (J2000):01h 51m 56.02s Declination (J2000): +53deg 27m 39.0s found at the distance of about 550 pc. The dust color temperature was found to lie in the range 18.02 K to 39.56 K. An offset of about 21 K suggests that the structure is not independently evolved, discrete source may play significant role in structure formation mechanisms. The study of flux variation along major and minor axis of structure showed that mass is concentrate at the center of structure. The total mass of the gas structure was found to be about 1.1432× 1031Kg. The Jeans mass was found to be 1.17 x 1033Kg, more than that of the total mass of the structure, suggest no clue of star formation.The Himalayan Physics Vol. 6 & 7, April 2017 (76-79)

scholarly journals A STUDY OF A PULSAR WIND DRIVEN STRUCTURE IN FAR-INFRARED IRAS MAP AT LATTITUDE -10º

2017 ◽  
Vol 22 (1) ◽  
pp. 1-9
Author(s):  
Ajay Kumar Jha ◽  
Binil Aryal
Keyword(s):  
Far Infrared ◽  
Density Variation ◽  
Color Temperature ◽  
Galactic Latitude ◽  
Dust Structure ◽  
Infrared Astronomical Satellite ◽  
Mass Profile ◽  
Using Data ◽  
Astronomical Satellite ◽  
Galactic Longitude

A systematic search of dust structure in the far infrared (100 μm and 60 μm) IRAS (Infrared Astronomical Satellite) survey was performed using Sky View Observatory. In order to find the possible candidate, we used SIMBAD database to locate discrete sources in the region. A deep cavity-like isolated far infrared dust structure (size ~ 4.46 pc × 2.23 pc) at galactic longitude: 284.360o, galactic latitude: -9.549o was found at the distance of about 375 pc. We have studied the flux density variation and then calculated temperature and mass profile of the dust and excess mass using data reduction software ALADIN 7.5 within this region. The dust color temperature was found to lie in the range 23.40 K to 29.28 K. An offset temperature of about 6.0 K was found. The total mass of the dust structure was found to be about 2.55×1027 kg and the excess mass per pixel was 2.52×1024 kg. We also studied the rate of mass loading around the structure. The energy of the pulsar required to create that in homogeneity in the structure was calculated to be 5.04×1036 J. Possible explanations of results will be presented.Journal of Institute of Science and Technology, 2017, 22 (1): 1-9

scholarly journals Far-Infrared Emission from Clumpy Irregular Galaxies

1987 ◽  
Vol 115 ◽  
pp. 647-647
Author(s):  
U. Klein ◽  
J. Heidmann ◽  
R. Wielebinski ◽  
E. Wunderlich
Keyword(s):  
Star Formation ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Hubble Constant ◽  
Far Infrared ◽  
Hii Regions ◽  
Infrared Emission ◽  
Star Forming ◽  
Irregular Galaxies

The four clumpy irregular galaxies Mkr 8, 296,297 and 325 have been observed by IRAS. All galaxies have been detected in at least two of the four detector bands. The ratios of the 100 to 60-m flux densities are comparable to those of HII regions or violently star forming galaxies. The average star formation rate in clumpy irregular galaxies is of the order of a few solar masses per year (based on their average far-infrared luminosity and a Hubble constant of 75 km s−1 Mpc−1.

scholarly journals Multiwavelength radio observations of a brightest cluster galaxy at z = 1.71: detection of a modest active galactic nucleus and evidence for extended star formation

2019 ◽  
Vol 487 (1) ◽  
pp. 1210-1217 ◽  
Author(s):  
Ariane Trudeau ◽  
Tracy Webb ◽  
Julie Hlavacek-Larrondo ◽  
Allison Noble ◽  
Marie-Lou Gendron-Marsolais ◽  
...  
Keyword(s):  
Star Formation ◽  
Active Galactic Nucleus ◽  
Spectral Energy Distribution ◽  
Galaxy Cluster ◽  
Far Infrared ◽  
Infrared Emission ◽  
Spectral Energy ◽  
Radio Observations ◽  
Cluster Galaxy ◽  
Star Forming

ABSTRACT We present deep, multiwavelength radio observations of SpARCS104922.6 + 564032.5, a z = 1.71 galaxy cluster with a starbursting core. Observations were made with the Karl G. Jansky Very Large Array (JVLA) in three bands: 1–2 GHz, 4–8 GHz, and 8–12 GHz. We detect a radio source coincident with the brightest cluster galaxy (BCG) that has a spectral index of α = 0.44 ± 0.29 and is indicative of emission from an active galactic nucleus. The radio luminosity is consistent with the average luminosity of the lower redshift BCG sample, but the flux densities are 6σ below the predicted values of the star-forming spectral energy distribution based on far infrared data. Our new fit fails to simultaneously describe the far infrared and radio fluxes. This, coupled with the fact that no other bright source is detected in the vicinity of the BCG implies that the star formation region, traced by the infrared emission, is extended or clumpy and not located directly within the BCG. Thus, we suggest that the star-forming core might not be driven by a single major wet merger, but rather by several smaller galaxies stripped of their gas or by a displaced cooling flow, although more data are needed to confirm any of those scenarios.

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 Study of Dust Properties of two Far Infrared Cavities near by Asymptotic Giant Branch stars under Infrared Astronomical Satellite Maps

2020 ◽  
pp. 60-71
Author(s):  
M. Tiwari ◽  
S.P. Gautam ◽  
A. Silwal ◽  
S. Subedi ◽  
A. Paudel ◽  
...  
Keyword(s):  
Galactic Plane ◽  
Far Infrared ◽  
Asymptotic Giant Branch ◽  
Color Temperature ◽  
Dust Particles ◽  
Planck Function ◽  
Visual Extinction ◽  
Contour Plots ◽  
Infrared Astronomical Satellite ◽  
Astronomical Satellite

The physical properties such as dust color temperature, dust mass, visual extinction, and Planck function with their distribution in the core region of two far-infrared cavities, namely FIC16-37 (size ~ 4.79 pc x 3.06 pc) located at R.A. (J2000): 16h 33m 57.25s & Dec. (J2000): -37d 47m 04.3s, and FIC12-58 (size ~ 22.54 pc x 14.84 pc) located at R.A. (J2000): 12h 52m 50.08s & Dec. (J2000): -58d 08m 55.02s, found within a galactic plane -10o  to +10o  nearby Asymptotic Giant Branch (AGB) stars namely AGB15-38 (R.A. (J2000): 15h 37m 40.74s & Dec. (J2000): -38d 20m 24.6s), and AGB12-57 (R.A (J2000): 12h 56m 38.50s & Dec. (J2000): -57d 54m 34.70s), respectively were studied using Infrared Astronomical Satellite (IRAS) survey. The dust color temperature was found to lie in the range of 23.95 ± 0.25 K to 23.44 ± 0.27 K with an offset about 0.5 K for FIC16-37, and 24.88 ± 0.27 K to 23.63 ± 0.98 K with an offset about 1 K for FIC12-58. The low offset in the dust color temperature indicated the symmetric distribution of density and temperature. The total mass of the cavities FIC16-37 and FIC12-58 were found to be 0.053 M☉ and 0.78 M☉, respectively. The contour plots of mass distribution of both of the cavities was found to follow the cosmological principle, suggesting the homogeneous and isotropic distribution of dust masses. The plot between temperature and visual extinction showed a negative correlation, suggesting that higher temperature has lower visual extinction and vice-versa. The distribution of Planck function along major and minor diameters of both of the cavities was found to be non-uniform, indicating oscillation of dust particles to get dynamical equilibrium. It further suggested the role of pressure-driven events nearby both cavities and suggested that dust particles are not in thermal equilibrium along the diameters.

scholarly journals Far infrared cavity of a post C-rich AGB star under IRAS survey

BIBECHANA ◽  
2017 ◽  
Vol 15 ◽  
pp. 90-96
Author(s):  
A K Gautam ◽  
B Aryal
Keyword(s):  
Physical Properties ◽  
Flux Density ◽  
Temperature Variation ◽  
Far Infrared ◽  
Symmetric Distribution ◽  
Color Temperature ◽  
Dust Mass ◽  
H 51 ◽  
Low Offset

In this paper, we discuss about the physical properties of the dusty environment around the mass losing carbon rich post AGB star located at R.A. (J2000) =06 h 53m 01s and Dec (J2000) =-02o 16’ 00”, in the far infrared  IRAS maps. A cavity like structure (major diameter ∼ 103.3 pc & minor diameter ∼33.1 pc) is found to lie at R.A. (J2000)= 06 h 51 m 54.02 s and DEC (J2000) =  -01o 35’ 43”, located at a distance ∼ 6.11 kpc from the star. We studied the distribution of flux density, dust color temperature, dust mass  in the cavity. The dust color temperature is found to lie in the range 18.7 K to 20.5 K which shows the cavity is isolated and  independently evolved. Such a low offset temperature variation shows that there is symmetric outflow or symmetric distribution of density and temperature. It further suggests that our structure is bigger in size and is far away from the far infrared loops(kk loops). The cavity may be in thermally pulsating phase.  A possible explanation of the results will be discussed.BIBECHANA 90 (2018) 96

scholarly journals Study of a Far Infrared Cavity at 60 μm and 100 μm IRAS Map around the Carbon-Rich AGB Star at Galactic Latitude 8.6°

2020 ◽  
Vol 13 (13) ◽  
pp. 14-19
Author(s):  
A.K. Gautam ◽  
B. Aryal
Keyword(s):  
Flux Density ◽  
Far Infrared ◽  
Color Temperature ◽  
Galactic Latitude ◽  
Planck Function ◽  
Visual Extinction ◽  
Dust Mass

In this paper, we discussed about the dusty environment of the far infrared cavity around the AGB star located at R.A. (J2000) =01h41m 01s and Dec (J2000) = 71° 04’ 00 9, lying within far infrared loop G125+09 6 in the far infrared IRAS maps. A cavity like structure (major diameter ∼2.55pc & minor diameter ∼0.77pc) is found to lie at R.A. (J2000) = 01h46m57.2s and DEC (J2000) = 71°24’57.1”, located at a distance ∼ 220pc from the star. We studied the distribution of flux density, dust color temperature, dust mass, visual extinction in the cavity. We further studied the distribution Planck function along extension and compression, distribution of dust color temperature along square of the major and minor diameters. The dust color temperature is found to lie in the range (19.7±1.25) K to (21.1±0.55)K which shows the cavity is isolated and stable. A possible explanation of the results will be discussed.

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