J/A+A/698/A246 WISE 12um exozodi candidates within 10pc (Huang+, 2025)
WISE 12 µm search for exozodi candidates within 10 parsecs.
Huang D., Liu Q., Wyatt M.C., Kennedy G.M.
<Astron. Astrophys. 698, A246 (2025)>
=2025A&A...698A.246H 2025A&A...698A.246H (SIMBAD/NED BibCode)
ADC_Keywords: Stars, nearby ; Photometry, infrared ; Effective temperatures
Keywords: methods: data analysis - zodiacal dust - stars: general -
infrared: stars
Abstract:
The search for extra-terrestrial life is one of the ultimate goals for
future exoplanet-seeking missions while one of the major challenges
these missions face is the possible presence of warm dust, referred to
as "exozodiacal" dust, near the target stars or within their habitable
zone. Therefore, it is critical to identify which stars possess
exozodiacal dust and quantify their exozodiacal emission levels. In
this study, we conducted a search for exozodi candidates within 10
parsecs using the Reyle sample. We performed proper motion
calculations and cross-matched the sample with the WISE and 2MASS
database, resulting in 339 preliminary target samples. We further
analyzed the infrared radiation characteristics of these targets,
using spectral energy distribution (SED) fitting to predict
photometric flux levels in the infrared and searching for 3sigma
excesses in the WISE W3 band. During the further selection process, we
applied various analysis methods to perform rigorous validation. We
identified 5 exozodi candidates all of which are brown dwarfs (BDs).
Given the clustering in candidate spectral types, we expect that these
are not true exozodi candidates, rather the apparent excess arises
from the inability of the BD photosphere models to accurately
represent the SEDs of objects at the L-T transition. Indeed for the
object DENIS J025503.3-470049, excess is likely due to silicate clouds
in the BD atmosphere. We suggest that a more stringent 5sigma excess
is required to infer excess for this spectral type. The detection rate
(0/339) in our sample shows that less than 1% of M stars have exozodi
above 21% excess levels. This is consistent with the rate of exozodi
at similar level towards FGK stars in the Kennedy & Wyatt sample
(25/24,174). We provide upper limits on the 12 micron exozodi emission
for the sample, which is typically at 21% relative to the star. For
most stars, in particular the low mass M stars, this is the first such
upper limit in the literature.
Description:
Table 1 presents the basic stellar properties and photometric data of
the Sample B stars, including the object name (from the Reyle
sample), spectral type, stellar distance from Earth, effective
temperature derived from VOSA SED fitting, observed flux in the
ALLWISE W3 band, predicted photospheric flux in the same band, the
significance of flux excess in the W3 band (chi_12), the ratio of
excess flux to predicted photospheric flux at 12 micron
(Fexcess/F12,phot), and its upper limit, defined as the larger value
between 3sigmatot/F12,phot and 3sigma.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 118 339 The stellar basic properties and photometric
data of the Sample B stars
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See also:
J/A+A/650/A201 : 10 parsec sample in the Gaia era first update (Reyle+, 2021)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 27 A27 --- Name Name of the objects
29- 33 A5 --- SpType Spectral type
35- 41 F7.4 pc Dist Distance
43- 48 F6.4 pc e_Dist Distance uncertainty
50- 54 I5 K Teff Effective temperature
56- 65 F10.3 mJy F12obs Observed flux in the W3 band
67- 75 F9.3 mJy e_F12obs Observed uncertainty in the W3 band
77- 86 F10.3 mJy F12phot Predicted photospheric flux in
the W3 band
88- 97 F10.3 mJy e_F12phot Predicted photospheric uncertainty
in the W3 band
99-105 F7.3 --- chi12 Flux excess significance
107-112 F6.3 --- Fexcess/F12phot Fexcess/F12,phot at 12 micron
114-118 F5.3 --- F12ul Upper limit at 12 micron
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Acknowledgements:
Qiong Liu, qliu1(at)gzu.edu.cn
(End) Patricia Vannier [CDS] 09-May-2025