Models for the evolution of the spectral energy distribution of elliptical galaxies from ultraviolet to far-infrared wavelengths

1994 ◽  
Vol 422 ◽  
pp. 81 ◽  
Author(s):  
P. Mazzei ◽  
G. de Zotti ◽  
C. Xu
Keyword(s):  
Energy Distribution ◽  
Spectral Energy Distribution ◽  
Far Infrared ◽  
Elliptical Galaxies ◽  
Spectral Energy ◽  
Infrared Wavelengths

scholarly journals Revised SED of the triple protostellar system VLA 1623−2417

2018 ◽  
Vol 615 ◽  
pp. L14 ◽  
Author(s):  
N. M. Murillo ◽  
D. Harsono ◽  
M. McClure ◽  
S.-P. Lai ◽  
M. R. Hogerheijde
Keyword(s):  
Energy Distribution ◽  
Near Infrared ◽  
Spectral Energy Distribution ◽  
Spectral Energy ◽  
Gas Emission ◽  
Circumstellar Gas ◽  
Infrared Wavelengths ◽  
Previous Assumption

Context. VLA 1623−2417 is a triple protostellar system deeply embedded in Ophiuchus A. Sources A and B have a separation of 1.1″, making their study difficult beyond the submillimeter regime. Lack of circumstellar gas emission suggested that VLA 1623−2417 B has a very cold envelope and is much younger than source A, which is generally considered the prototypical Class 0 source. Aims. We explore the consequences of new ALMA Band 9 data on the spectral energy distribution (SED) of VLA 1623−2417 and their inferred nature. Methods. We constructed and analyzed the SED of each component in VLA 1623−2417 using dust continuum observations spanning from centimeter to near-infrared wavelengths. Results. The ALMA Band 9 data presented in this work show that the SED of VLA 1623−2417 B does not peak at 850 µm as previously expected, but instead presents the same shape as VLA 1623−2417 A at wavelengths shorter than 450 µm. Conclusions. The results presented in this work indicate that the previous assumption that the flux in Herschel and Spitzer observations is solely dominated by VLA 1623−2417 A is not valid, and instead, VLA 1623−2417 B most likely contributes a significant portion of the flux at λ < 450 µm. These results, however, do not explain the lack of circumstellar gas emission and puzzling nature of VLA 1623−2417 B.

scholarly journals Far-infrared photometry of OJ 287 with the Herschel Space Observatory

2018 ◽  
Vol 610 ◽  
pp. A74
Author(s):  
Mark Kidger ◽  
Staszek Zola ◽  
Mauri Valtonen ◽  
Anne Lähteenmäki ◽  
Emilia Järvelä ◽  
...  
Keyword(s):  
Energy Distribution ◽  
Light Curve ◽  
Spectral Index ◽  
Spectral Energy Distribution ◽  
Low Frequency ◽  
Far Infrared ◽  
Small Degree ◽  
Spectral Energy ◽  
Space Observatory ◽  
Near Ir

Context. The blazar OJ 287 has shown a ≈12 year quasi-periodicity over more than a century, in addition to the common properties of violent variability in all frequency ranges. It is the strongest known candidate to have a binary singularity in its central engine. Aim. We aim to better understand the different emission components by searching for correlated variability in the flux over four decades of frequency measurements. Methods. We combined data at frequencies from the millimetric to the visible to characterise the multifrequency light curve in April and May 2010. This includes the only photometric observations of OJ 287 made with the Herschel Space Observatory: five epochs of data obtained over 33 days at 250, 350, and 500 μm with Herschel-SPIRE. Results. Although we find that the variability at 37 GHz on timescales of a few weeks correlates with the visible to near-IR spectral energy distribution, there is a small degree of reddening in the continuum at lower flux levels that is revealed by the decreasing rate of decline in the light curve at lower frequencies. However, we see no clear evidence that a rapid flare detected in the light curve during our monitoring in the visible to near-IR light curve is seen either in the Herschel data or at 37 GHz, suggesting a low-frequency cut-off in the spectrum of such flares. Conclusions.We see only marginal evidence of variability in the observations with Herschel over a month, although this may be principally due to the poor sampling. The spectral energy distribution between 37 GHz and the visible can be characterised by two components of approximately constant spectral index: a visible to far-IR component of spectral index α = −0.95, and a far-IR to millimetric spectral index of α = −0.43. There is no evidence of an excess of emission that would be consistent with the 60 μmdust bump found in many active galactic nuclei.

scholarly journals Hot & cold dust in M31: the resolved SED of Andromeda

2011 ◽  
Vol 7 (S284) ◽  
pp. 112-116
Author(s):  
Brent Groves ◽  
Oliver Krause ◽  
Keyword(s):  
Energy Distribution ◽  
Spectral Energy Distribution ◽  
Far Infrared ◽  
Spectral Energy ◽  
Space Observatory ◽  
Photometric Observations ◽  
Total Luminosity ◽  
Andromeda Galaxy ◽  
Cold Dust ◽  
Insight Into

AbstractDue to its proximity, the Andromeda galaxy (M31, NGC 224) offers a unique insight into how the spectra of stars, dust, and gas combine to form the integrated Spectral Energy Distribution (SED) of galaxies. We introduce here Herschel Space Observatory PACS and SPIRE photometric observations of M31 which cover the far-infrared to sub-mm wavelengths (70-500 μm). These new observations reveal that the total IR luminosity of M31 is relatively weak, with LIR=109.65L⊙, only 10% of the total luminosity of M31. However, as seen in the previous studies of M31, the IR luminosity is dominated by a 10 kpc ring in all Herschel bands. This is distinct from the optical, where the bulge in the central 2kpc, dominates the luminosity, clearly demonstrating how different components at distinct positions in a galaxy contribute to make the integrated SED.

scholarly journals Herschel Detects a Massive Dust Reservoir in Supernova 1987A

Science ◽  
2011 ◽  
Vol 333 (6047) ◽  
pp. 1258-1261 ◽  
Author(s):  
M. Matsuura ◽  
E. Dwek ◽  
M. Meixner ◽  
M. Otsuka ◽  
B. Babler ◽  
...  
Keyword(s):  
Energy Distribution ◽  
Spectral Energy Distribution ◽  
Far Infrared ◽  
Large Magellanic Cloud ◽  
Spectral Energy ◽  
The Sun ◽  
Supernova 1987A ◽  
Dust Mass ◽  
Cold Dust ◽  
Very High

We report far-infrared and submillimeter observations of supernova 1987A, the star whose explosion was observed on 23 February 1987 in the Large Magellanic Cloud, a galaxy located 160,000 light years away. The observations reveal the presence of a population of cold dust grains radiating with a temperature of about 17 to 23 kelvin at a rate of about 220 times the luminosity of the Sun. The intensity and spectral energy distribution of the emission suggest a dust mass of about 0.4 to 0.7 times the mass of the Sun. The radiation must originate from the supernova ejecta and requires the efficient precipitation of all refractory material into dust. Our observations imply that supernovae can produce the large dust masses detected in young galaxies at very high redshifts.

scholarly journals The GROUnd-based Secondary Eclipse project - GROUSE

2010 ◽  
Vol 6 (S276) ◽  
pp. 487-488
Author(s):  
Ernst de Mooij ◽  
Remco de Kok ◽  
Bas Nefs ◽  
Matteo Brogi ◽  
Ignas Snellen
Keyword(s):  
Energy Distribution ◽  
Wavelength Range ◽  
Near Infrared ◽  
Spectral Energy Distribution ◽  
Energy Budgets ◽  
Spectral Energy ◽  
Hot Jupiters ◽  
Eclipse Observations ◽  
Infrared Wavelengths ◽  
Optical Wavelengths

AbstractSecondary eclipse observations of exoplanets at near-infrared wavelengths are important to constrain the energy budgets of hot-Jupiters, since they probe the radiation from the planet's atmosphere at the peak of the spectral energy distribution. Since this wavelength range is accesible from the ground, we have started the GROUnd-based Secondary Eclipse (GROUSE) project. As part of the GROUSE project, we target a sample of hot-Jupiters at near-infrared and optical wavelengths. Planets include TrES-3b, HAT-P-1, WASP-18b and WASP-33b.

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