Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: L-band Spectroscopy with Magellan-AO/Clio2: First Results on Young
  Low-Mass Companions   L-band spectroscopy is a powerful probe of cool low-gravity atmospheres: The
P, Q, and R branch fundamental transitions of methane near 3.3 $\mu$m provide a
sensitive probe of carbon chemistry; cloud thickness modifies the spectral
slope across the band; and H$_{3}^{+}$ opacity can be used to detect aurorae.
Many directly imaged gas-giant companions to nearby young stars exhibit L-band
fluxes distinct from the field population of brown dwarfs at the same effective
temperature. Here we describe commissioning the L-band spectroscopic mode of
Clio2, the 1-5 $\mu$m instrument behind the Magellan adaptive-optics system. We
use this system to measure L-band spectra of directly imaged companions. Our
spectra are generally consistent with the parameters derived from previous
near-infrared spectra for these late M to early L type objects. Therefore,
deviations from the field sequence are constrained to occur below 1500 K. This
range includes the L-T transition for field objects and suggests that observed
discrepancies are due to differences in cloud structure and CO/CH$_{4}$
chemistry.

11
The categories of this paper are: hep-lat
17
The categories of this paper are: q-fin
19
The categories of this paper are: eess
27
The categories of this paper are: comp-gas
14
The categories of this paper are: math-ph
4
The categories of this paper are: cond-mat
35
The categories of this paper are: mtrl-th
10
The categories of this paper are: q-bio
9
The categories of this paper are: nlin
12
The categories of this paper are: nucl-th
3
The categories of this paper are: physics
37
The categories of this paper are: supr-con
33
The categories of this paper are: plasm-ph
0
The categories of this paper are: hep-ph
15
The categories of this paper are: nucl-ex
16
The categories of this paper are: stat