Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Optical Spectra of Type Ia Supernovae at z=0.46 and z=1.2   We present optical spectra, obtained with the Keck 10-m telescope, of two
high-redshift type Ia supernovae (SNe Ia) discovered by the High-z Supernova
Search Team: SN 1999ff at z=0.455 and SN 1999fv at z~1.2, the highest-redshift
published SN Ia spectrum. Both SNe were at maximum light when the spectra were
taken. We compare our high-z spectra with low-z normal and peculiar SNe Ia as
well as with SNe Ic, Ib, and II. There are no significant differences between
SN 1999ff and normal SNe Ia at low redshift. SN 1999fv appears to be a SN Ia
and does not resemble the most peculiar nearby SNe Ia.

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The categories of this paper are: q-bio
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The categories of this paper are: dg-ga
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The categories of this paper are: ao-sci
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The categories of this paper are: chem-ph
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The categories of this paper are: chao-dyn
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The categories of this paper are: hep-th
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The categories of this paper are: hep-ph
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The categories of this paper are: acc-phys
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The categories of this paper are: cond-mat
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The categories of this paper are: plasm-ph
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The categories of this paper are: gr-qc
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The categories of this paper are: stat
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The categories of this paper are: alg-geom
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The categories of this paper are: cmp-lg
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The categories of this paper are: atom-ph
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The categories of this paper are: quant-ph