Mass Loss History of Evolved Stars (MLHES) Excavated by AKARI

2018 ◽  
Vol 14 (S343) ◽  
pp. 516-517
Author(s):  
Toshiya Ueta ◽  
Andrew J. Torres ◽  
Hideyuki Izumiura ◽  
Issei Yamamura
Keyword(s):  
Circumstellar Dust ◽  
Linear Distribution ◽  
Dust Shells ◽  
Evolved Stars ◽  
Dust Component ◽  
History Of ◽  
Infrared Astronomical Satellite ◽  
Cold Dust ◽  
Ir Emission ◽  
Astronomical Satellite

AbstractWe performed a far-IR imaging survey of the circumstellar dust shells of 144 evolved stars as a mission program of the AKARI infrared astronomical satellite. Our objectives were to characterize the far-IR surface brightness distributions of the cold dust component in the circumstellar dust shells. We found that (1) far-IR emission was detected from all but one object, (2) roughly 60–70 % of the target sources showed some extension, (3) 29 sources were newly resolved in the far-IR in the vicinity of the target sources, (4) the results of photometry measurements were reasonable with respect to the entries in the AKARI/FIS Bright Source Catalogue, and (5) an IR two-color diagram would place the target sources in a roughly linear distribution that may correlate with the age of the circumstellar dust shell.

scholarly journals Smoking supernovae

2007 ◽  
Vol 6 (2) ◽  
pp. 159-167 ◽  
Author(s):  
H.L. Gomez ◽  
S.A. Eales ◽  
L. Dunne
Keyword(s):  
Supernova Remnants ◽  
Supernova Remnant ◽  
Infrared Space Observatory ◽  
Cassiopeia A ◽  
Dust Clouds ◽  
Bolometer Array ◽  
Infrared Astronomical Satellite ◽  
Cold Dust ◽  
Astronomical Satellite ◽  
Rule Out

AbstractThe question ‘Are supernovae important sources of dust?’ is a contentious one. Observations with the Infrared Astronomical Satellite (IRAS) and the Infrared Space Observatory (ISO) only detected very small amounts of hot dust in supernova remnants. Here, we review observations of two young Galactic remnants with the Submillimetre Common User Bolometer Array (SCUBA), which imply that large quantities of dust are produced by supernovae. The association of dust with the Cassiopeia A remnant is in question owing to the contamination of foreground material. In this paper, we compare the emission from cold dust with CO emission towards Kepler’s supernova remnant. We detect very little CO at the location of the submillimetre peaks. A comparison of masses from the CO and the dust clouds are made, and we estimate the 3σ upper limit on the gas-to-dust ratios to be in the range 20–60. These results suggest that we cannot yet rule out freshly-formed or swept-up circumstellar dust in Kepler’s supernova remnant.

scholarly journals Astromineralogy: Crystalline silicates

2003 ◽  
Vol 209 ◽  
pp. 291-298
Author(s):  
F. J. Molster
Keyword(s):  
Circumstellar Dust ◽  
Space Observatory ◽  
Infrared Space Observatory ◽  
Evolved Stars ◽  
Formation History ◽  
Long Time ◽  
Dust Component ◽  
The Many ◽  
Dust Distribution ◽  
First Time

Silicates are the most abundant dust component in our Universe. For a long time it was generally assumed that around evolved stars only amorphous silicates were present. The infrared space observatory (ISO; Kessler et al. 1996) discovered that the abundance of crystalline silicates can be quite significant. Thanks to ISO it is now for the first time possible to determine the exact chemical composition of the silicates, and in contrast to the amorphous silicates, the crystalline silicates turned out to be very Fe-poor (i.e. forsterite and enstatite). Careful investigations of the spectra of crystalline silicates in several conditions, both in laboratory and in space, have taken place. It was found that not only the abundance of the crystalline silicates is related to the spatial distribution of the circumstellar dust, but also the shape of the features differs between sources with and without a disk-like dust distribution. Because of the many spectral features of the crystalline silicates one can easily determine temperatures and mass ratios for enstatite and forsterite. But even single features contain interesting information. The position and FWHM of the 69.0 micron forsterite feature, might be used as a new diagnostic of characteristic temperatures of (crystalline) silicate dust, while the 33.6 micron forsterite feature bears evidence for its formation history.

scholarly journals Gaia DR2 data and the evolutionary status of eight high-velocity hot post-AGB candidates

2020 ◽  
Vol 72 (6) ◽  
Author(s):  
Mudumba Parthasarathy ◽  
Tadafumi Matsuno ◽  
Wako Aoki
Keyword(s):  
Effective Temperature ◽  
High Velocity ◽  
Circumstellar Dust ◽  
Evolutionary Status ◽  
Agb Stars ◽  
Horizontal Branch ◽  
Dust Shells ◽  
The Past ◽  
Gaia Dr2 ◽  
Branch Star

Abstract From Gaia DR2 data of eight high-velocity hot post-AGB candidates, LS 3593, LSE 148, LS 5107, HD 172324, HD 214539, LS IV −12 111, LS III +52 24, and LS 3099, we found that six of them have accurate parallaxes which made it possible to derive their distances, absolute visual magnitudes (MV) and luminosity (log L/L⊙). All the stars except LS 5107 have an accurate effective temperature (Teff) in the literature. Some of these stars are metal poor, and some of them do not have circumstellar dust shells. In the past, the distances of some stars were estimated to be 6 kpc, which we find to be incorrect. The accurate Gaia DR2 parallaxes show that they are relatively nearby, post-AGB stars. When compared with post-AGB evolutionary tracks we find their initial masses to be in the range 1 M⊙ to 2 M⊙. We find the luminosity of LSE 148 to be significantly lower than that of post-AGB stars, suggesting that this is a post-horizontal-branch star or post-early-AGB star. LS 3593 and LS 5107 are new high-velocity hot post-AGB stars from Gaia DR2.

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 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.

Paleomagnetic history of the Mealy dykes of Labrador, Canada

1983 ◽  
Vol 20 (12) ◽  
pp. 1818-1833 ◽  
Author(s):  
J. K. Park ◽  
R. F. Emslie
Keyword(s):  
The Other ◽  
Magnetic Mineral ◽  
Magnetic Minerals ◽  
Linear Distribution ◽  
Tectonic Zone ◽  
Magnetic Components ◽  
History Of ◽  
Component C ◽  
A Site

Paleomagnetic analysis of the Mealy diabase dykes of Labrador reveals magnetizations that predate the Grenville event at about 1000 Ma. These dykes intrude the Mealy Mountains anorthositic complex in the Grenville Structural Province. They are well south of the Grenville Front Tectonic Zone, but were apparently never subjected to temperatures as high as 500 °C during their post-consolidation history.Four distinct magnetic components were uncovered by thermal and alternating field treatments and a fifth remained unresolved. The major magnetic mineral present, titanomagnetite, is thought to record two magnetic directions acquired during cooling from magmatic temperatures. These are B (D = 305°, I = −76°; N = 18 sites; κ = 12; α95 = 11°) and A (D = 095°, I = +52°; N = 20 sites; κ = 46; α95 = 5°). Component B has much within-site dispersion. The other two components, C (D = 274°, I = −47°; N = 10 sites; κ = 15; α95 = 13°) and D (D = 292°, I = −74°; κ = 5; α95 = 31°), probably reside in magnetite and pyrrhotite, respectively. Component C, antiparallel to A, was probably acquired at about the same time as A. We suggest that C and A represent the first stable magnetizations retained by the dykes following an extensive period of cooling and re-equilibration of the magnetic minerals. Components B and D, which agree in direction, represent a later stage of cooling.Component B has a pole at 148°E, 34°S (δp = 18°, δm = 19°) in agreement with regional metamorphic poles from the Grenville; A, however, has a pole at 173°W, 23°S (δp = 5°, δm = 7°), which apparently "sees through" the peak in Grenville activity. The A site poles have a linear distribution along the Keweenawan Track and probably relate to an age between 1000 and 1150 Ma.

Sign in / Sign up

Export Citation Format

Share Document