33 research outputs found
Far-Ultraviolet Spectroscopy of Star-Forming Regions in Nearby Galaxies: Stellar Populations and Abundance Indicators
We present FUSE spectroscopy and supporting data for star-forming regions in
nearby galaxies, to examine their massive-star content and explore the use of
abundance and population indicators in this spectral range for high-redshift
galaxies. New far-ultraviolet spectra are shown for four bright H II regions in
M33 (NGC 588, 592, 595, and 604), the H II region NGC 5461 in M101, and the
starburst nucleus of NGC 7714, supplemented by the very-low-metallicity galaxy
I Zw 18. In each case, we see strong Milky Way absorption systems from H2, but
intrinsic absorption within each galaxy is weak or undetectable, perhaps
because of the "UV bias" in which reddened stars which lie behind
molecular-rich areas are also heavily reddened. We see striking changes in the
stellar-wind lines from these populations with metallicity, suggesting that C
II, C III, C IV, N II, N III, and P V lines are potential tracers of stellar
metallicity in star-forming galaxies. Three of these relations - involving N
IV, C III, and P V - are nearly linear over the range from O/H=0.05--0.8 solar.
The major difference in continuum shapes among these systems is that the giant
H II complex NGC 604 has a stronger continuum shortward of 950 A than any other
object in this sample. Small-number statistics would likely go in the other
direction; we favor this as the result of a discrete star-forming event ~3 Myr
ago, as suggested by previous studies of its stellar population. (Supported by
NASA grant NAG5-8959)Comment: Astronomical Journal, in press (July 2004). 8 figures; before
publication, full-resolution figures are available as a single PDF file from
http://www.astr.ua.edu/keel/fusefigs.pd
Study of the Relation between the Spiral Arm Pitch Angle and the Kinetic Energy of Random Motions of the Host Spiral Galaxies, A
In this work, we report a relation between the kinetic energy of random motions of the corresponding host galaxies and spiral arm pitch angles (Mdynσ2- P), (M*σ2- P) where Mdyn is the bulge dynamical mass, M* is bulge stellar mass, and σ is the velocity dispersion of the host galaxy bulge. We measured the spiral arm pitch angle (P) for a sample of Spitzer/IRAC 3.6-μm images of 54 spiral galaxies, estimated by using a 2D Fast Fourier Transform decomposition technique (2DFFT). We selected a sample of nearly face-on spiral galaxies and used IRAF ellipse to determine the ellipticity and major-axis position angle in order to deproject the images to face-on, and using a 2D Fast Fourier Transform decomposition technique, we determined the spiral arm pitch angles. We estimated the kinetic energy of random motions of the corresponding host galaxies (Mdynσ, M*σ2) by using Mdyn, M*, and σ, where the stellar velocity dispersion (σ) of the bulge was taken from the literature. We determined the bulge dynamical mass (Mdyn) using the virial theorem, and the bulge stellar mass (M*) was estimated by using the bulge 3.6-μm luminosity with the appropriate stellar mass-to-light ratio (M/L)
Galaxy bulges and their massive black holes: a review
With references to both key and oft-forgotten pioneering works, this article
starts by presenting a review into how we came to believe in the existence of
massive black holes at the centres of galaxies. It then presents the historical
development of the near-linear (black hole)-(host spheroid) mass relation,
before explaining why this has recently been dramatically revised. Past
disagreement over the slope of the (black hole)-(velocity dispersion) relation
is also explained, and the discovery of sub-structure within the (black
hole)-(velocity dispersion) diagram is discussed. As the search for the
fundamental connection between massive black holes and their host galaxies
continues, the competing array of additional black hole mass scaling relations
for samples of predominantly inactive galaxies are presented.Comment: Invited (15 Feb. 2014) review article (submitted 16 Nov. 2014). 590
references, 9 figures, 25 pages in emulateApJ format. To appear in "Galactic
Bulges", E. Laurikainen, R.F. Peletier, and D.A. Gadotti (eds.), Springer
Publishin
Images in clinical urology. Nail of glans penis.
A 56-year-old man presented with a "nail" growing at the base of his glans penis. The tumor was locally excised, and microscopic examination revealed papillomatosis and hyperkeratosis of the malpighian epithelium, with a strong inflammatory reaction of the chorion and signs of local microinvasion, as well as the presence of well-differentiated squamous epithelial cells. The surgical margins were negative. The differential diagnosis was made between a benign papillomatous proliferation and verrucous carcinoma
Néphrectomie par laparoscopie: aspects techniques [Laparoscopic nephrectomy: technical aspects]
The laparoscopic approach has emerged as a valid option for surgical management of kidney cancer, as well as a few benign pathologies. The immediate benefits of laparoscopy are well established and include less estimated blood loss, decreased pain, shorter perioperative convalescence, and improved cosmesis. Long-term oncologic outcomes of patients treated laparoscopically for kidney tumors are similar to those of open surgery
La prostatite. [Prostatitis]
Prostatitis, and particulary chronic pelvic pain syndrome, is a very challenging field in urology. Large randomized placebo treatment trials are necessary for a better evaluation of the different therapeutic options. This article is a review of the evolution in prostatitis diagnostic and actual treatments
Thermothérapie transurétrale de la prostate : Un traitement efficace et non invasif de l'hyperplasie bénigne de la prostate
Depuis ses débuts en 1989, la thermothérapie transurétrale de la prostate s'est lentement fait une place de choix dans l'arsenal thérapeutique de l'hyperplasie bénigne de la prostate (HBP) symptomatique. Même si au début les protocoles de traitement proposés tenaient plus de l'expérimentation et, il faut bien le dire, ne donnaient que des résultats décevants, force est de reconnaître que le matériel et les logiciels mis à disposition actuellement permettent aux urologues de proposer un traitement en ambulatoire, court (30 minutes) et en anesthésie locale, des symptômes mictionnels obstructifs dus à l'HBP, particulièrement aux patients âgés et polymorbides
Hormonothérapie et prise en charge du cancer prostatique hormono-résistant
La prise en charge du cancer hormono-résistant reste à l'heure actuelle un des plus importants challenges de l'uro-oncologie. Même si les différentes possibilités thérapeutiques n'apportent pas la preuve d'un gain de survie des patients ou d'un retard signlficatif de la progression tumorale, elles n'en apportent pas moins une amélioration des symptômes et de la qualité de vie des patients. Cet article fait un Inventaire des différentes prises en charge possibles reconnues à ce jour