Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spectroscopy of horizontal branch stars in NGC6752 - Anomalous results
  on atmospheric parameters and masses   We used the ESO VLT-FORS2 facility to collect low-resolution spectra of 51
targets distributed along the Horizontal Branch. We determined atmospheric
parameters by comparison with theoretical models through standard fitting
routines, and masses by basic equations. Results are in general in good
agreement with previous works, although not always with theoretical
expectations for cooler stars (Teff<15000 K). The calculated color excess is
systematically lower than literature values, pointing towards a possible
underestimation of effective temperatures. Moreover, we find two groups of
stars at Teff=14000 K and at Teff=27000$ K that present anomalies with respect
to the general trend and expectations. We suppose that the three peculiar
bright stars at Teff=14000 K are probably affected by an enhanced stellar wind.
For the eight Extreme Horizontal Branch stars at Teff=27000 K which show
unusually high masses we find no plausible explanation. While most of our
results agree well with the predictions of standard horizontal branch
evolution, we still have problems with the low masses we derive in certain
temperature ranges. We believe that Kurucz ATLAS9 LTE model atmospheres with
solar-scaled abundances are probably inadequate for these temperature ranges.
Concerning the group of anomalous stars at Teff=27000 K, a Kolmogorov-Smirnov
test indicates that there is only an 8.4% probability that these stars are
randomly drawn from the general distribution in the color-magnitude diagram.
This is not conclusive but points out that these stars could be both (and
independently) spectroscopically and photometrically peculiar with respect to
the general Extreme Horizontal Branch population.

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The categories of this paper are: supr-con
10
The categories of this paper are: q-bio
2
The categories of this paper are: math
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The categories of this paper are: bayes-an
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The categories of this paper are: funct-an
4
The categories of this paper are: cond-mat
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The categories of this paper are: nlin
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The categories of this paper are: quant-ph
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The categories of this paper are: nucl-ex
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The categories of this paper are: stat
1
The categories of this paper are: cs
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The categories of this paper are: eess
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The categories of this paper are: chem-ph
0
The categories of this paper are: hep-ph
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The categories of this paper are: dg-ga
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The categories of this paper are: hep-th