Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Morphological number-count and redshift distributions to I < 26 from the
  Hubble Deep Field: Implications for the evolution of Ellipticals, Spirals and
  Irregulars   We combine the photometric redshift data of Fernandez-Soto et al. (1997) with
the morphological data of Odewahn et al. (1996) for all galaxies with I < 26.0
detected in the Hubble Deep Field. From this combined catalog we generate the
morphological galaxy number-counts and corresponding redshift distributions and
compare these to the predictions of high normalization zero- and passive-
evolution models. From this comparison we conclude the following: (1) E/S0s are
seen in numbers and over a redshift range consistent with zero- or minimal
passive- evolution to I = 24. Beyond this limit fewer E/S0s are observed than
predicted implying a net negative evolutionary process --- luminosity dimming,
disassembly or masking by dust --- at I > 24. (2) Spiral galaxies are present
in numbers consistent with zero- evolution predictions to I = 22. Beyond this
magnitude some net- positive evolution is required. Although the number-counts
are consistent with the passive-evolution predictions to I=26.0 the redshift
distributions favor number AND luminosity evolution. (3) There is no obvious
explanation for the late-type/irregular class and this category requires
further subdivision. While a small fraction of the population lies at low
redshift (i.e. true irregulars), the majority lie at redshifts, 1 < z < 3. At z
> 1.5 mergers are frequent and, taken in conjunction with the absence of normal
spirals at z > 2, the logical inference is that they represent the progenitors
of normal spirals forming via hierarchical merging.

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The categories of this paper are: atom-ph
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The categories of this paper are: adap-org
35
The categories of this paper are: mtrl-th
12
The categories of this paper are: nucl-th
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The categories of this paper are: quant-ph
0
The categories of this paper are: hep-ph
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The categories of this paper are: q-alg
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The categories of this paper are: chao-dyn
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The categories of this paper are: ao-sci
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The categories of this paper are: econ
10
The categories of this paper are: q-bio
5
The categories of this paper are: gr-qc
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The categories of this paper are: math-ph
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The categories of this paper are: funct-an
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The categories of this paper are: cs
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The categories of this paper are: cmp-lg