1,332 research outputs found
The Discovery of a Molecular Complex in the Tidal Arms near NGC 3077
We present the discovery of a giant molecular complex (r=350 pc, M_ vir=10^7
M_sun) in the tidal arms south-east of NGC 3077, a member of the M 81 triplet.
The complex is clearly detected in the 12CO (J=1-0) transition at five
independent positions. The position relative to NGC 3077, the systemic velocity
(v_hel=14km/s) and the cloud averaged line width (15km/s) indicate that the
object is not related to Galactic cirrus but is extragalactic. The tidal HI arm
where the molecular complex is located has an total HI mass of M_HI=3x10^8
M_sun. This tidal material was presumably stripped off the outer parts of NGC
3077 during the closest encounter with M 81, about 3x10^8 years ago. After the
complex detected along a torn-out spiral arm of M 81 by Brouillet et al., it is
the second of its kind reported so far. Based on published optical
observations, we have no evidence for on--going star formation in the newly
detected molecular complex. Since the system has all the ingredients to form
stars in the future, we speculate that it might eventually resemble the young
dwarf galaxies in the M 81 group.Comment: 12 pages (including 3 figures), accepted for publication in the ApJ
Letter
Star Forming Objects in the Tidal Tails of Compact Groups
A search for star forming objects belonging to tidal tails has been carried
out in a sample of deep Halpha images of 16 compact groups of galaxies. A total
of 36 objects with Halpha luminosity larger than 10^38 erg s-1 have been
detected in five groups. The fraction of the total Halpha luminosity of their
respective parent galaxies shown by the tidal objects is always below 5% except
for the tidal features of HCG95, whose Halpha luminosity amounts to 65% of the
total luminosity. Out of this 36 objects, 9 star forming tidal dwarf galaxy
candidates have been finally identified on the basis of their projected
distances to the nuclei of the parent galaxies and their total Halpha
luminosities. Overall, the observed properties of the candidates resemble those
previously reported for the so-called tidal dwarf galaxies.Comment: 5 gif figures. Accepted for publication in Astrophysical Journa
The orbital poles of Milky Way satellite galaxies: a rotationally supported disc-of-satellites
Available proper motion measurements of Milky Way (MW) satellite galaxies are
used to calculate their orbital poles and projected uncertainties. These are
compared to a set of recent cold dark-matter (CDM) simulations, tailored
specifically to solve the MW satellite problem. We show that the CDM satellite
orbital poles are fully consistent with being drawn from a random distribution,
while the MW satellite orbital poles indicate that the disc-of-satellites of
the Milky Way is rotationally supported. Furthermore, the bootstrapping
analysis of the spatial distribution of theoretical CDM satellites also shows
that they are consistent with being randomly drawn. The theoretical CDM
satellite population thus shows a significantly different orbital and spatial
distribution than the MW satellites, most probably indicating that the majority
of the latter are of tidal origin rather than being DM dominated
sub-structures. A statistic is presented that can be used to test a possible
correlation of satellite galaxy orbits with their spatial distribution.Comment: Accepted for publication in Ap
Challenges and successes in the treatment of hemophilia: the story of a patient with severe hemophilia A and high-titer inhibitors
In the past, patients with severe hemophilia have suffered a substantially reduced quality of life with frequent bleeding episodes, disabling arthropathy, and shorter life expectancy. In addition, methods of treatment and management have been costly and time-consuming, and have placed a considerable burden on patients’ physical and psychological well-being. With the advent of the on-demand therapy and prophylactic treatment paradigm, patients have been able to receive care with less interruption of daily activities. Treatments may be more challenging for hemophiliacs with inhibitors to replacement factor; however, recent advances in the use of bypassing agents and immune tolerance therapy have enabled them to aggressively manage their disease while maintaining their independence. This review focuses on the challenges of treating such a severe hemophiliac through examination of the lifetime experience of a young adult male with a severe form of congenital hemophilia A. At this stage of his life, the patient has minimal disabilities and is inhibitor-free through optimal care and strong family support. His aspiration to pursue a productive life has led him to a career in medicine. After receiving his medical degree, he pursued a specialty in the treatment of hemophilia. By assisting other hemophilia patients, he exemplifies both the rewards of persevering through episodes of bleeding and other complications and the fact that disabilities can be minimized when managed meticulously and in a timely fashion to enable a productive and dignified life
Computing the Weil representation of a superelliptic curve
We study the Weil representation of a curve over a -adic field with
potential reduction of compact type. We show that can be reconstructed
from its stable reduction. For superelliptic curves of the form at
primes whose residue characteristic is prime to the exponent we make
this explicit
Magnetic properties of Gd_xY_{1-x}Fe_2Zn_{20}: dilute, large, moments in a nearly ferromagnetic Fermi liquid
Single crystals of the dilute, rare earth bearing, pseudo-ternary series,
Gd_xY_{1-x}Fe_2Zn_{20} were grown out of Zn-rich solution. Measurements of
magnetization, resistivity and heat capacity on Gd_xY_{1-x}Fe_2Zn_{20} samples
reveal ferromagnetic order of Gd^{3+} local moments across virtually the whole
series (). The magnetic properties of this series, including the
ferromagnetic ordering, the reduced saturated moments at base temperature, the
deviation of the susceptibilities from Curie-Weiss law and the anomalies in the
resistivity, are understood within the frame work of dilute,
moments (Gd^{3+}) embedded in a nearly ferromagnetic Fermi liquid
(YFe_2Zn_{20}). The s-d model is employed to further explain the variation of
with x as well as the temperature dependences of of the
susceptibilities
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