3,392 research outputs found
Structure and Kinematics of Molecular Disks in Fast-Rotator Early-Type Galaxies
We present interferometric observations resolving the CO emission in the four
gas-rich lenticular galaxies NGC 3032, NGC 4150, NGC 4459, and NGC 4526, and we
compare the CO distribution and kinematics to those of the stars and ionized
gas. Counterrotation documents an external origin for the gas in at least one
case (NGC 3032), and the comparisons to stellar and ionized gas substructures
in all four galaxies offer insights into their formation histories. The
molecular gas is found in kpc-scale disks with mostly regular kinematics and
average surface densities of 100 to 200 \msunsqpc. The disks are well aligned
with the stellar photometric and kinematic axes. In the two more luminous Virgo
Cluster members NGC 4459 and NGC 4526 the molecular gas shows excellent
agreement with circular velocities derived independently from detailed modeling
of stellar kinematic data. There are also two puzzling instances of
disagreements between stellar kinematics and gas kinematics on sub-kpc scales.
In the inner arcseconds of NGC 3032 the CO velocities are significantly lower
than the inferred circular velocities, and the reasons may possibly be related
to the external origin of the gas but are not well understood. In addition, the
very young population of stars in the core of NGC 4150 appears to have the
opposite sense of rotation from the molecular gas.Comment: ApJ, accepte
Evidence of Climate-Induced Range Contractions in Bull Trout \u3ci\u3eSalvelinus confluentus\u3c/i\u3e in a Rocky Mountain Watersehd, U.S.A.
Many freshwater fish species are considered vulnerable to stream temperature warming associated with climate change because they are ectothermic, yet there are surprisingly few studies documenting changes in distributions. Streams and rivers in the U.S. Rocky Mountains have been warming for several decades. At the same time these systems have been experiencing an increase in the severity and frequency of wildfires, which often results in habitat changes including increased water temperatures. We resampled 74 sites across a Rocky Mountain watershed 17 to 20 years after initial samples to determine whether there were trends in bull trout occurrence associated with temperature, wildfire, or other habitat variables. We found that site abandonment probabilities (0.36) were significantly higher than colonization probabilities (0.13), which indicated a reduction in the number of occupied sites. Site abandonment probabilities were greater at low elevations with warm temperatures. Other covariates, such as the presence of wildfire, nonnative brook trout, proximity to areas with many adults, and various stream habitat descriptors, were not associated with changes in probability of occupancy. Higher abandonment probabilities at low elevation for bull trout provide initial evidence validating the predictions made by bioclimatic models that bull trout populations will retreat to higher, cooler thermal refuges as water temperatures increase. The geographic breadth of these declines across the region is unknown but the approach of revisiting historical sites using an occupancy framework provides a useful template for additional assessments
The Discovery of a Giant H-alpha Filament in NGC 7213
The nearby Seyfert galaxy NGC 7213 has been imaged in H-alpha and HI with the
CTIO 1.5 m telescope and with the Australia Telescope Compact Array (ATCA),
respectively. Optically NGC 7213 looks undisturbed and relatively featureless
but the continuum-subtracted H-alpha image shows a 19 kpc long filament located
approximately 18.6 kpc from the nucleus. The H-alpha filament could be neutral
gas photo-ionized by the active nucleus, as has been suggested for the Seyfert
galaxy NGC 5252, or shock-ionized by a jet interacting with the surrounding HI,
as has been suggested for the radio galaxy PKS 2240-41. The HI map reveals NGC
7213 to be a highly disturbed system suggesting a past merging event.Comment: 14 pages including 4 figures and 1 table. Figures 1-4 are in jpeg
format; Better quality images can be retrieved in postscript format at
ftp://charon.nmsu.edu/pub/shameed/ ; Accepted for publication in ApJ Letter
Screening For Maternal Postpartum Depression In The Pediatric Primary Care Setting: An Educational Project
Abstract
The birth of a baby can bring about an array of powerful emotions that range from joy and excitement to feelings of anxiety, worry, and depression. A majority of mothers experience postpartum baby blues which normally begins 2-3 days after delivery and can last for up to 2-3 weeks, but some mothers experience a more severe form known as postpartum depression (PPD). PPD can be mistaken for baby blues at first, but the signs and symptoms do not diminish and can continue to worsen. Postpartum depression signs and symptoms include withdrawing from friends and family, severe mood swings, excessive crying, increased or decreased appetite, loss of interest or pleasure in doing things, and difficulty bonding or making a connection with the newborn (Mayo Clinic, 2022). PPD can also lead to suicidal ideation as well as thoughts of harming the infant. If left untreated, this can increase the baby’s risk for developmental delays and impaired social development.
Given the effects that PPD can have on the mother and infant, it is vital that this diagnosis is caught and treated early, but unfortunately there are women who miss their postpartum follow-up appointment with their obstetrician. The American Academy of Pediatrics recognized this gap in missed diagnoses and recommended that pediatric providers screen for maternal PPD at the 1, 2, 4, and 6- month well-child visits (Morehead, 2020). The two project sites do not follow this recommendation, so an educational PowerPoint focusing on the epidemiology of PPD, validated screening tools, and the significance of PPD was presented to the pediatric providers and data from the pre-test and post-test survey were analyzed. Although not statistically significant, the educational intervention had an impact on their knowledge relating to postpartum depression
On the Classification of UGC1382 as a Giant Low Surface Brightness Galaxy
We provide evidence that UGC1382, long believed to be a passive elliptical
galaxy, is actually a giant low surface brightness (GLSB) galaxy which rivals
the archetypical GLSB Malin 1 in size. Like other GLSB galaxies, it has two
components: a high surface brightness disk galaxy surrounded by an extended low
surface brightness (LSB) disk. For UGC1382, the central component is a
lenticular system with an effective radius of 6 kpc. Beyond this, the LSB disk
has an effective radius of ~38 kpc and an extrapolated central surface
brightness of ~26 mag/arcsec^2. Both components have a combined stellar mass of
~8x10^10 M_sun, and are embedded in a massive (10^10 M_sun) low-density (<3
M_sun/pc^2) HI disk with a radius of 110 kpc, making this one of the largest
isolated disk galaxies known. The system resides in a massive dark matter halo
of at least 2x10^12 M_sun. Although possibly part of a small group, its low
density environment likely plays a role in the formation and retention of the
giant LSB and HI disks. We model the spectral energy distributions and find
that the LSB disk is likely older than the lenticular component. UGC1382 has
UV-optical colors typical of galaxies transitioning through the green valley.
Within the LSB disk are spiral arms forming stars at extremely low
efficiencies. The gas depletion time scale of ~10^11 yr suggests that UGC1382
may be a very long term resident of the green valley. We find that the
formation and evolution of the LSB disk is best explained by the accretion of
gas-rich LSB dwarf galaxies.Comment: 17 pages, 16 figures, 4 tables; accepted to the Astrophysical Journa
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