Dust Structure around AGB Star in 60μm and 100 μm IRAS Survey at Latitude 16.10°

Mass Profile ◽

A systematic search in the range of J2000 coordinate system provided by K.W. Shu & Y.J. Kwon (2011) of dust structure in the far infrared (100 μm and 60 μm) IRAS (Infrared Astronomical Satellite) survey was performed using Sky View virtual Observatory (1) so that some interesting isolated cavity structures surrounding the cavity structure were expected. The FITS images downloaded from sky view (1) was processed using software Aladin v 2.5. A cavity like structure (major diameter ∼ 3.57 pc & minor diameter ∼ 1.19 pc) lies in the coordinate of R.A. (J2000) 06h 31m 05s and DEC (J2000) 16d 06m 00s was found at the distance ∼ 310 pc (5). We studied the flux density variation and the temperature variation about major diameter, minor diameter and the distance between minimum temperature and minimum flux within the structure. We observed the variation of the temperature is 20.53 K to 21.42 K, with the offset of about 0.89 K, which shows the cavity is independently evolved. The mass profile of each pixel of the structure was also calculated using these temperature.The Himalayan Physics Vol. 6 & 7, April 2017 (48-53)

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

Journal of Institute of Science and Technology ◽

10.3126/jist.v22i1.17733 ◽

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 ◽

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

A Study of Dust Structure around AGB Star in 60 and 100 μm IRAS Survey at Latitude 54.68º

Journal of Nepal Physical Society ◽

10.3126/jnphyssoc.v4i1.17339 ◽

2017 ◽

Vol 4 (1) ◽

pp. 67

Author(s):

Arjun Kumar Gautam ◽

Binil Aryal

Keyword(s):

Minimum Temperature ◽

Far Infrared ◽

Density Variation ◽

Asymptotic Giant Branch ◽

Infrared Range ◽

Virtual Observatory ◽

Agb Stars ◽

Dust Structure ◽

Mass Losses ◽

Mass Profile

We have studied about the evolution of Asymptotic Giant Branch (AGB) stars, mass losses from them and a systematic search of AGB stars in J2000 coordinate system provided by K. W. Shu & Y. J. Kwon (2011) of dust structure in the far infrared range (100 μm and 60 μm). For dust structure IRAS survey was performed using Sky View virtual Observatory. The FITS images downloaded from sky view was processed using software Aladin v 2.5. A cavity like structure (major diameter∼1.93 pc & minor diameter∼ 0.89 pc) lies in the coordinate of R. A. (J2000) 04h 15m 03s and DEC (J2000) 54d 41m 00s was found at the distance∼ 240 pc. We studied the flux density variation and the temperature variation about major diameter, minor diameter and the distance between minimum temperature and minimum flux within the structure. We observed the variation of the temperature is 20.53 K to 21.09 K, with the offset of about 0.56 K, which show the cavity is independently evolved. The mass profile of each pixel of the structure was also calculated using this temperature.Journal of Nepal Physical Society Volume 4, Issue 1, February 2017, Page: 67-77

Study of far infrared cavity around a post AGB star under IRAS survey at galactic latitude -3°

BIBECHANA ◽

10.3126/bibechana.v16i0.20960 ◽

2018 ◽

Vol 16 ◽

pp. 23-30

Author(s):

A K Gautam ◽

B Aryal

Keyword(s):

Local Thermodynamic Equilibrium ◽

Far Infrared ◽

Density Variation ◽

Color Temperature ◽

Galactic Latitude ◽

Cavity Structure ◽

Mass Profile ◽

Using Data ◽

A systematic search of dust structure in the far infrared (100 μm and 60 μm) under Infrared Astronomical Satellite (IRAS) survey was performed using Sky View virtual Observatory. In order to find the possible candidate of cavity structure not yet studied, we used SIMBAD database to locate discrete sources in the region. A new relatively symmetric spherical cavity like structure (size: 1.354 pc x 0.971 pc) at R.A.(J2000) =08h 03m 01.65s, Dec.(J2000) = -360 35' 47.9" was found at the distance of about 2800 pc. In this article, we have calculated dust color temperature, dust mass and size. We also studied the flux density variation and then calculated temperature and mass profile of the dust of p-AGB star using data reduction software Aladin2.5 and Aladin8.0. We have studied a cavity like structure centered at R.A.(J2000) = 08h 04m 07.21s, Dec.(J2000) = -370 11' 48.0". The dust color temperature is found to lie in the range 21.6 ± 0.09 K to 22.5 ± 0.05 K with an offset of 0.9 K. Such low off set suggests that the post AGB is in local thermodynamic equilibrium. The total mass of the dust in the cavity structure is found about 5.93 x 1025 Kg (0.00003M⊙)BIBECHANA 1 6 (2019) 23-30

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

Journal of Nepal Physical Society ◽

10.3126/jnphyssoc.v4i1.17334 ◽

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 ◽

Astronomical Satellite ◽

Pulsar Evolution

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 1023 Kg. The energy required to create that inhomogeneity in the structure is calculated to be 3.24 x1035 J.Journal of Nepal Physical Society Volume 4, Issue 1, February 2017, Page: 33-41

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

Journal of Nepal Physical Society ◽

10.3126/jnphyssoc.v7i2.38631 ◽

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 ◽

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.

Dust Structure around two Asymptotic Giant Stars at Latitude 32° & 40.67°

Himalayan Physics ◽

10.3126/hj.v6i0.18356 ◽

2017 ◽

pp. 41-47

Author(s):

A. K. Jha ◽

D. R. Upadhyay

Keyword(s):

Infrared Image ◽

Far Infrared ◽

Density Variation ◽

Asymptotic Giant Branch ◽

Color Temperature ◽

Dust Structure ◽

Outflow Velocity ◽

Cavity Structure ◽

Mass Outflow ◽

Using Data

We studied the dust structures in 60μm and 100μm infrared image around the two asymptotic giant branch (AGB) stars. A systematic search of dust structure in the far infrared (100 μm and 60 μm) Infrared Astronomical Satellite (IRAS) survey was performed using Sky View Observatory. In order to find the possible candidate of cavity structure not yet studied, we used SIMBAD database to locate discrete sources in the region. A new relatively symmetric spherical cavity like structure (size: 1.354 pc × 0.971 pc) for candidate I and (size: 1.424 pc × 0.925pc) for candidate II at R.A.(J2000) =04h46m13.84s, Dec.(J2000) = +32°31’39.6’’ and 05h05m59.58s; +40°40’33.4’’ respectively was found at the distance of about 280 pc and 390 pc. In this present work we have calculated the dust color temperature, mass, outflow velocity, energy and size. We also studied the flux density variation and then calculated temperature and mass profile of the dust and outflow nature of AGB wind using data reduction software’s Aladin v2.5 and Aladinv8.0. Our aim was to test how outflow can be seen in this region. We have studied two cavity-like structures. The dust color temperature is found to lie in the range 21.7 K to 35.6 K for candidate I and 18.5 K to 19.3 K, with an offset of about 14 K and 0.8 K respectively. An offset of 14 K suggests that the AGB is hot in early AGB phase now in late AGB stage. We expect deviation from symmetrical outflow, i.e., AGB wind probably prefer polytropic behaviour implies bipolar type wind whereas the offset 0.8 K for candidate II suggests that the AGB is in the symmetric AGB phase, i.e., early AGB stage. The total mass of the dust in the cavity structure is found about 5.93×1025 Kg (0.00003Mʘ) for candidate I and 1.95×1027Kg (0.001 Mʘ) for candidate II. In addition we have calculated outflow energy of C-rich AGB star along ISM using outflow velocity of our candidates. It is found that the outflow velocities are 12.96 ms-1 and 10.71 ms-1 respectively. For this we have calculated the value of speed of sound (Cs) and escape velocity (uesc). In this way we have determined outflow energy, i.e., 1.173×1025J and 2.766 × 1027J respectively.The Himalayan Physics Vol. 6 & 7, April 2017 (41-47)

Nuclear Starbursts in Barred Spirals

Symposium - International Astronomical Union ◽

10.1017/s007418090014166x ◽

1989 ◽

Vol 134 ◽

pp. 465-466

Author(s):

N.A. Devereux

Keyword(s):

Flux Ratio ◽

Far Infrared ◽

The first analysis of the Infrared Astronomical Satellite (IRAS) data revealed differences between barred and unbarred spirals. The study of Shapley-Ames galaxies, by De Jong et al (1984), revealed that barred spirals tend, on average, to be associated with “warmer” far infrared color temperatures and higher Lfir/Lblue ratios than unbarred spirals. In a related study Hawarden et al (1986) noted that barred and unbarred spirals could be partially segregated on the basis of the IRAS S25μm/S25μm flux ratio. Both sets of investigators attributed the differences, between barred and unbarred spirals, to a nuclear starburst in the barred types.

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

Himalayan Physics ◽

10.3126/hp.v9i01.40193 ◽

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 ◽

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.

Temperature and Mass Profile of Far-infrared Skeleton Nebula

Himalayan Physics ◽

10.3126/hj.v1i0.5162 ◽

2011 ◽

Vol 1 ◽

pp. 1-3

Author(s):

Binil Aryal

Keyword(s):

Star Formation ◽

Flux Density ◽

Far Infrared ◽

Density Variation ◽

Color Temperature ◽

External Radiation ◽

Colour Temperature ◽

Mass Profile ◽

Dust Grain ◽

Map Location

Flux density variation of a newly discovered isolated far-infrared interstellar nebula (R.A. = 08h27m, Dec. = +25°54' (J2000)) is studied at 100 μm and 60 μm Infrared Astronomical Survey (IRAS) maps. The nebula contains two bright condensations ("nuclei") and several prominent filaments. The dust color temperature is estimated throughout the nebular region by dividing the 100 μm map by the 60 μm map and comparing the resulting flux I(100μm)/I(60μm) values at each map location with the values given for dust grain models by Dwek (1986). It is found that the dust colour temperature of the southern nucleus is 34±4 K and the temperature of its northern counterpart 32±4 K. The eastern filamentary structures are slightly cooler (20±2 K) than the western filamentary structures (26±3 K). Hence, the locations of the maximum emission i.e. the nuclei of the nebula are warmer than their filaments. It is interestingly noticed that there are no hints of star formation in the nebula, suggesting interaction with ambient matter or the presence of unknown external radiation. Possible explanations of the results will be explained.Key words: Nebula; Temperature; IRASThe Himalayan Physics Vol.1, No.1, May, 2010Page:1-3Uploaded Date: 28 July, 2011

Chandra Observation of the AKARI NEP Deep Field

Proceedings of the International Astronomical Union ◽

10.1017/s1743921314003949 ◽

2013 ◽

Vol 9 (S304) ◽

pp. 244-244

Author(s):

Takamitsu Miyaji ◽

M. Krumpe ◽

H. Brunner ◽

Keyword(s):

Rest Frame ◽

Field Survey ◽

Dust Emission ◽

Infrared Camera ◽

Far Infrared ◽

Source Detection ◽

Team Members ◽

X Ray ◽

AbstractThe AKARI NEP Deep Field Survey is an international multiwavelength survey over 0.4 deg2 of the sky. This is the deepest survey made by the InfraRed Camera (IRC) of the infrared astronomical satellite AKARI with 9 filters continuously covering the 2-25 μm range. This has been supplemented by other ground-based and space multiwavelength data ranging from X-ray (Chandra), UV (GALEX), Optical-NIR (Subaru Sprime-cam, CFHT/WIRCAM, CFHT/Megacam, KPNO Flamningos among others for imagings as well as Keck Diemos, Subaru Focas, Subaru FMOS, WIYN Hydra, and GTC OSIRIS for spectra), far-infrared (Herschel) and radio (WSRT and e-Merlin). The uniqueness of the field lies in the availability of four filters between 9-18 μm, which fall into the Spitzer gap between the IRAC and MIPS instruments. This made this field one of the deepest at ~ 15 μm and the deepest among those with similar solid angles. This enabled us to make sensitive MIR detection of AGN candidates around z ~ 1. The MIR selection is based on hot dust emission in the AGN torus and is efficient in detecting highly obscured Compton-thick AGN population. A number of team members have worked (e.g. Hanami et al. 2012) or are working on a catalog of AGN candidates in this field. In this presentation, we report the results of the Chandra observations on this field. The field was covered by 15 overlapping Chandra ACIS-I observations (including our own and from archive) with a total exposure of 310 ks, detecting ~ 500 X-ray sources. We explain our improved source detection procedure for highly overlapped Chandra images and results. We utilize the stacking analysis (both in the observed and rest-frame) of the MIR AGN candidates that are not detected individually. The stacking analysis is expected to detect the summed X-ray flux from scattered components and Fe-lines. The results are discussed in terms of quantifying the Compton-thick populations at z ~ 1.