Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Herbig-Haro flows in L1641N   We have used the 2.56m Nordic Optical Telescope (NOT) to observe two deep
fields in L1641N, selected on the basis of previous shock studies, using the
2.12 micron transition of H2 (and a Ks filter to sample the continuum) for a
total exposure time of 4.6 h (72 min Ks) in the overlapping region. The
resulting high-resolution mosaic shows numerous new shocks and resolves many
known shocks into multiple components. Using previous observations taken 9
years earlier we calculate a proper motion map and combine this with Spitzer 24
micron observations of the embedded young stars. The combined H2 mosaic shows
many new shocks and faint structures in the HH flows. From the proper motion
map we find that most HH objects belong to two major bi-polar HH flows, the
large-scale roughly North-South oriented flow from central L1641N and a
previously unseen HH flow in eastern L1641N. Combining the tangential velocity
map with the mid-IR Spitzer images, two very likely outflow sources are found.
The outflow source of the eastern flow, L1641N-172, is found to be the
currently brightest mid-IR source in L1641N and seem to have brightened
considerably during the past 20 years. We make the first detection of this
source in the near-IR (Ks) and also find a near-IR reflection nebula pointing
at the source, probably the illuminated walls of a cone-shaped cavity cleared
out by the eastern lobe of the outflow. Extending a line from the eastern
outflow source along the proper motion vector we find that HH 301 and HH 302
(almost 1 pc away) belong to this new HH flow.

32
The categories of this paper are: atom-ph
9
The categories of this paper are: nlin
14
The categories of this paper are: math-ph
5
The categories of this paper are: gr-qc
16
The categories of this paper are: stat
37
The categories of this paper are: supr-con
13
The categories of this paper are: quant-ph
4
The categories of this paper are: cond-mat
12
The categories of this paper are: nucl-th
26
The categories of this paper are: bayes-an
29
The categories of this paper are: funct-an
7
The categories of this paper are: hep-th
33
The categories of this paper are: plasm-ph
30
The categories of this paper are: q-alg
18
The categories of this paper are: econ
25
The categories of this paper are: patt-sol