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http://hdl.handle.net/20.500.12386/33470
Campo DC | Valore | Lingua |
---|---|---|
dc.contributor.author | SPAGNA, Alessandro | en_US |
dc.contributor.author | PERINA, SIBILLA | en_US |
dc.contributor.author | RE FIORENTIN, Paola | en_US |
dc.contributor.author | Litsiou, Evdoxia | en_US |
dc.date.accessioned | 2023-02-15T10:40:08Z | - |
dc.date.available | 2023-02-15T10:40:08Z | - |
dc.date.issued | 2023 | en_US |
dc.identifier.uri | http://hdl.handle.net/20.500.12386/33470 | - |
dc.description.abstract | In order to investigate the feasibility of an all-sky guide star catalogue for an FGS operating in the FIR, we cross-match the sources selected in three test regions from the IRAS PSC and from the Spitzer surveys with both the AllWISE catalogue and Gaia DR3. We find 143 and 318 matched IRAS sources within 20° from the NGP and within 2° from the GC, respectively. In addition, we identify 3607 sources from the Spizer/SEP survey and 5398 sources from the Spitzer/MIPSGAL survey within 1° from the GC. We compare the AllWISE magnitudes W4 (22 um) versus the IRAS [25] and Spitzer/MIPS [24], and we confirm that W4 = [24] = [25] due to the similarity of these three passbands. By means of the color-color plots, G–W1 vs. W2–W3, we are able to identify and classify stars and extragalactic objects (e.g. galaxies and QSO’s) in the fields towards intermediate and high Galactic latitudes. We show evidence that stars without IR excess have null color-indexes, so that W2 = W3 = W4 = [24], as the spectral energy distribution in the MIR and FIR of the stars outside the Galactic plane can be well represented by the Rayleigh–Jeans approximation. Moreover, extragalactic sources show positive color-indexes of about W3–W4 2 mag, due to the thermal emission from the dust in the ISM. The Galactic Center is a much more challenging region because of the stellar crowding, as well as the strong optical extinction associated with a high sky IR background. Here, we assume that all the sources are classified as “Stars”. Actually, the distribution [24] vs. W4 in the GC region shows a larger spread and systematic offset with respect to the corresponding distribution in the SEP region. Similar results are found for the other passbands [24] vs. W3 or [24] vs. W2. These effects may be due to the non-negligible IR extinction towards the Galactic Center and/or by an instrumental systematic bias produced by the high sky background that contaminates the photometric aperture of the lower resolution WISE data. We derive the photometric transformations from W3 to the [24] passband for both the SEP and GC regions within the magnitude range defined by the sensitivity of AllWISE and Spitzer/MIPS surveys. For the stellar sources in the SEP region, we find accuracy increasing from 0.04 mag (W3 < 7) to 0.18 mag (W3 = 11), with a systematic error of about 0.04-0.07 mag. For non stellar sources with a 5 parameters astrometric solution (Nonstars1), we estimate a precision of 0.3-0.5 mag with systematic errors of about 0.1-0.2 mag in the magnitude range 8 < W3 < 14. For the faint non stellar sources with a 2 parameters astrometric solution (Nonstars2), the precision increases up to 0.6 mag. We point out that these values include the contribution of the photometric errors, \sigma_W3 and \sigma_[24], from the AllWISE and Spitzer/MIPS. The detailed statistics of the photometric residuals as a function of the magnitude W3, for the Stars and Nonstars1, are listed in Table 12.2. In order to further improve the accuracy of the transformations, we check the presence of additional color-terms. However, no significant color term is revealed. The photometric transformation for the stellar sources in the GC field shows an offset of 0.8 mag offset with respect to the bisector, [24] = W3, that may depend on a systematic bias affecting AllWISE photometry due to high IR background. Finally, by means of synthetic photometry based on the SWIRE template library, we validate the transformation to the [24] passaband for the extragalactic sources and estimate a new transformation for a test [28] passband, which results about 1.5 mag fainter than that to [24]. | en_US |
dc.language.iso | eng | en_US |
dc.title | The far IR photometric propagation analysis | en_US |
dc.type | Research report | - |
dc.relation.medium | STAMPA | en_US |
dc.relation.volume | OATO-FIR-FGS-TNO-001 | en_US |
dc.relation.numberofpages | 43 | en_US |
dc.type.referee | REF_2 | en_US |
dc.description.note | This document presents the results of Task 2a of the “Far IR photometric propagation analysis” study conducted by the OATo Team for Thales Alenia Space Italia (TASI) within the “Far IR Risk Mitigation” project commissioned by ESA. | en_US |
dc.description.numberofauthors | 2 | en_US |
dc.description.international | sì | en_US |
dc.contributor.country | ITA | en_US |
dc.contributor.country | GRC | en_US |
dc.relation.scientificsector | FIS/05 - ASTRONOMIA E ASTROFISICA | en_US |
dc.type.miur | 298 Altro | - |
dc.relation.versioning | Issue 2, Rev. 1 | en_US |
dc.contributor.approved | Spagna, A; Sarasso M. | en_US |
dc.description.oa | 2 – prodotto con deroga per i casi previsti dalla Policy (allegare il modulo al passo 5-Carica) | en_US |
item.cerifentitytype | Publications | - |
item.grantfulltext | reserved | - |
item.fulltext | With Fulltext | - |
item.openairecristype | http://purl.org/coar/resource_type/c_18cf | - |
item.openairetype | Research report | - |
item.languageiso639-1 | en | - |
crisitem.author.dept | O.A. Torino | - |
crisitem.author.dept | O.A. Torino | - |
crisitem.author.dept | O.A. Torino | - |
crisitem.author.orcid | 0000-0003-1732-2412 | - |
crisitem.author.orcid | 0000-0001-6189-3883 | - |
crisitem.author.orcid | 0000-0002-4995-0475 | - |
È visualizzato nelle collezioni: | 4.03 Rapporti di progetto |
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OATO-FIR-FGS-TNO-001_v2.1.pdf | [Administrators only] Nota tecnica di progetto spaziale (ESA, TASI) | 3.74 MB | Adobe PDF |
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