318 research outputs found
Π‘ΠΏΠΎΡΠΎΠ± ΠΏΠΎΡΡΡΠΎΠ΅Π½ΠΈΡ ΠΈΠ½ΡΠ΅Π³ΡΠΈΡΠΎΠ²Π°Π½Π½ΠΎΠΉ ΠΈΠ½ΡΠΎΡΠΌΠ°ΡΠΈΠΎΠ½Π½ΠΎΠΉ ΡΡΠ΅Π΄Ρ Π½Π° Π±Π°Π·Π΅ ΡΠΈΡΡΠ΅ΠΌ ΡΠΏΡΠ°Π²Π»Π΅Π½ΠΈΡ Π΄Π°Π½Π½ΡΠΌΠΈ ΠΈ ΡΠΈΡΡΠ΅ΠΌ Π°Π²ΡΠΎΠΌΠ°ΡΠΈΠ·ΠΈΡΠΎΠ²Π°Π½Π½ΠΎΠ³ΠΎ ΠΏΡΠΎΠ΅ΠΊΡΠΈΡΠΎΠ²Π°Π½ΠΈΡ
Π Π°ΡΡΠΌΠΎΡΡΠ΅Π½Ρ Π°ΡΠΏΠ΅ΠΊΡΡ ΠΏΠΎΡΡΡΠΎΠ΅Π½ΠΈΡ Π΅Π΄ΠΈΠ½ΠΎΠ³ΠΎ ΠΈΠ½ΡΠΎΡΠΌΠ°ΡΠΈΠΎΠ½Π½ΠΎΠ³ΠΎ ΠΏΡΠΎΡΡΡΠ°Π½ΡΡΠ²Π° Π΄Π»Ρ ΡΠ°Π·ΡΠ°Π±ΠΎΡΠΊΠΈ Π²ΡΡΠΎΠΊΠΎΡΠ΅Ρ
Π½ΠΎΠ»ΠΎΠ³ΠΈΡΠ½ΠΎΠΉ ΠΏΡΠΎΠ΄ΡΠΊΡΠΈΠΈ, ΡΠ΅Π°Π»ΠΈΠ·ΠΎΠ²Π°Π½Π½ΠΎΠ³ΠΎ Π² Π²ΠΈΠ΄Π΅ ΠΏΡΠΎΠ³ΡΠ°ΠΌΠΌΠ½ΠΎΠ³ΠΎ Π²Π·Π°ΠΈΠΌΠΎΠ΄Π΅ΠΉΡΡΠ²ΠΈΡ ΡΠΈΡΡΠ΅ΠΌΡ ΡΠΏΡΠ°Π²Π»Π΅Π½ΠΈΡ Π΄Π°Π½Π½ΡΠΌΠΈ ΠΈ ΡΠΈΡΡΠ΅ΠΌ Π°Π²ΡΠΎΠΌΠ°ΡΠΈΠ·ΠΈΡΠΎΠ²Π°Π½Π½ΠΎΠ³ΠΎ ΠΏΡΠΎΠ΅ΠΊΡΠΈΡΠΎΠ²Π°Π½ΠΈΡ. ΠΡΠ΅Π΄Π»ΠΎΠΆΠ΅Π½Ρ ΡΡΠ΅Π±ΠΎΠ²Π°Π½ΠΈΡ ΠΊ ΠΈΠ½ΡΠ΅Π³ΡΠ°ΡΠΈΠΈ ΡΠΈΡΡΠ΅ΠΌ ΡΠΊΠ°Π·Π°Π½Π½ΡΡ
ΠΊΠ°ΡΠ΅Π³ΠΎΡΠΈΠΉ, ΡΡΡΡΠΊΡΡΡΠ° Ρ
ΡΠ°Π½Π΅Π½ΠΈΡ ΡΠΈΠΏΠΎΠ²ΡΡ
ΡΠΏΡΠ°Π²ΠΎΡΠ½ΡΡ
Π΄Π°Π½Π½ΡΡ
, Π°Π»Π³ΠΎΡΠΈΡΠΌΡ ΠΎΠ±ΠΌΠ΅Π½Π° ΠΈΠ½ΡΠΎΡΠΌΠ°ΡΠΈΠ΅ΠΉ ΠΌΠ΅ΠΆΠ΄Ρ ΠΈΠ½ΡΠ΅Π³ΡΠΈΡΡΠ΅ΠΌΡΠΌΠΈ ΠΈΠ½ΡΠΎΡΠΌΠ°ΡΠΈΠΎΠ½Π½ΡΠΌΠΈ ΡΠΈΡΡΠ΅ΠΌΠ°ΠΌΠΈ Ρ ΡΡΠ΅ΡΠΎΠΌ ΡΠΎΡΡΠΎΡΠ½ΠΈΠΉ ΠΆΠΈΠ·Π½Π΅Π½Π½ΠΎΠ³ΠΎ ΡΠΈΠΊΠ»Π° ΠΎΠ±ΡΠ΅ΠΊΡΠΎΠ² ΠΏΡΠΎΠ΅ΠΊΡΠΈΡΠΎΠ²Π°Π½ΠΈΡ
The Reddening-Free Decline Rate Versus Luminosity Relationship for Type Ia Supernovae
We develop a method for estimating the host galaxy dust extinction for type
Ia supernovae based on an observational coincidence first noted by Lira (1995),
who found that the B-V evolution during the period from 30-90 days after V
maximum is remarkably similar for all events, regardless of light curve shape.
This fact is used to calibrate the dependence of the B(max)-V(max) and
V(max)-I(max) colors on the light curve decline rate parameter delta-m15, which
can, in turn, be used to separately estimate the host galaxy extinction. Using
these methods to eliminate the effects of reddening, we reexamine the
functional form of the decline rate versus luminosity relationship and provide
an updated estimate of the Hubble constant of Ho = 63.3 +- 2.2(internal) +-
3.5(external) km/s/Mpc.Comment: 32 pages, 10 figures, AJ 1999 in pres
DeWitt Wallace Library Annual Report 2014-2015
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Long slit spectroscopy of a sample of isolated spirals with and without an AGN
We present the kinematical data obtained for a sample of active (Seyfert) and
non active isolated spiral galaxies, based on long slit spectra along several
position angles in the Halpha line region and, in some cases, in the Ca triplet
region as well. Gas velocity distributions are presented, together with a
simple circular rotation model that allows to determine the kinematical major
axes. Stellar velocity distributions are also shown. The main result is that
active and control galaxies seem to be equivalent in all kinematical aspects.
For both subsamples, the departure from pure circular rotation in some galaxies
can be explained by the presence of a bar and/or of a spiral arm. They also
present the same kind of peculiarities, in particular, S-shape structures are
quite common near the nuclear regions. They define very similar Tully-Fisher
relations. Emission line ratios are given for all the detected HII regions; the
analysis of the [NII]/Halpha metallicity indicator shows that active and
non-active galaxies have indistinguishable disk metallicities. These results
argue in favour of active and non-active isolated spiral galaxies having
essentially the same properties, in agreement with our previous results based
on the analysis of near infrared images. It appears now necessary to confirm
these results on a larger sample.Comment: 35 pages, 54 figures, Accepted for publication in Astronomy &
Astrophysics The full paper with its figures is available on the anonymous
account of ftp.iap.fr in /home/ftp/pub/from_users/durret/marquez.ps.gz (999
kb
A??es de extens?o na UFFS - Universidade Federal Da Fronteira Sul, campus Cerro Largo/RS, para o aprendizado de softwares gr?ficos como o autocad
O trabalho apresenta a experi?ncia da UFFS - Universidade Federal da Fronteira Sul ? Campus Cerro Largo/RS, na implanta??o das a??es de Extens?o Universit?ria, voltadas ao aprendizado de softwares gr?ficos com o AutoCAD, que viabilizam o desenho assistido por computador e ampliam os conhecimentos acerca do desenho t?cnico executado sem o aux?lio de prancheta. Acredita-se que o relato e registro dessa experi?ncia sejam relevantes j? que abordam a??es de extens?o desenvolvidas no contexto de universidades recentemente criadas, como a UFFS. O trabalho aborda quest?es pertinentes aos recursos e meios necess?rios para viabilizar cursos de extens?o nesta ?rea; ao uso e ? disponibilidade do espa?o f?sico de laborat?rios, dos equipamentos, do software e dos materiais did?ticos, entre outros. Tamb?m s?o discutidos alguns aspectos da intera??o entre a universidade e a comunidade relacionados ao processo de ensino-aprendizagem. A popula??o tem buscado apropriar-se de novas tecnologias, como o AutoCAD, visando a otimiza??o e o aprimoramento dos servi?os de desenho e/ou elabora??o de projetos t?cnicos. Assim, a cria??o de um curso de extens?o nesta ?rea vem atender ?s demandas locais e regionais, considerando-se que a regi?o das Miss?es vem retomando o seu crescimento a partir da constru??o de barragens e da instala??o de um Campus da
UFFS em Cerro Largo. Ent?o, foi proposto um Curso de Extens?o na modalidade
presencial - ?Desenho t?cnico sem prancheta, assistido por computador: Modulo
b?sico (30h) e M?dulo avan?ado (30h)?, que iniciou em mar?o de 2011 e, hoje, est?
na sua segunda edi??o. O curso objetiva instrumentalizar os participantes a atuarem
no desenvolvimento, na elabora??o e padroniza??o de projetos t?cnicos, levando-os
a compreender a linguagem gr?fica do desenho t?cnico assistido por computador e
a manipular uma s?rie de recursos do software AutoCAD, para a cria??o de
desenhos e modelos nos espa?os bi e tridimensional
The distance of M33 and the stellar population in its outskirts
We present deep V,I photometry of two $9.4' x 9.4' field in the outer regions
of the M33 galaxy. We obtain a robust detection of the luminosity of the Red
Giant Branch Tip (I{TRGB}=20.72 +- 0.08) from which we derived a new estimate
of the distance modulus of M33, (m-M)_0=24.64 +- 0.15, corresponding to a
distance D=847 +- 60 Kpc. By comparison of the color and magnitude of the
observed Red Giant Branch stars with ridge lines of template globular clusters
we obtained the photometric metallicity distribution of the considered fields
in three different metallicity scales. The derived metallicity distributions
are very similar over a range of distances from the galactic center 10' <= R <=
33', and are characterized by a well defined peak at [M/H] ~ -0.7 ([Fe/H] ~
-1.0, in the Zinn & West scale) and a weak metal-poor tail reaching [M/H] ~
-2.0. Our observations demonstrate that Red Giant Branch and Asymptotic Giant
Branch stars have a radial distribution that is much more extended than the
young MS stars associated with the star-forming disc.Comment: 10 pages,10 figures,accepted for publication in Astronomy &
Astrophysic
The dependence of HII region properties on global and local surface brightness within galaxy discs
Using B, R, and H-alpha images of roughly equal-sized samples of low surface
brightness (LSB) and high surface brightness (HSB) galaxies (~40 galaxies
apiece), we have explored the dependence of HII region properties on local and
global disc surface brightness. We have done this by constructing co-added HII
region luminosity functions (LFs) according to local and central disc surface
brightness and fitting Schechter functions to these LFs. The results show that
the shape of the HII region LF within LSB galaxies does not change noticeably
as different limiting (i.e., mu>mu_lim) local surface brightness values are
used. However, the LFs for HSB galaxies have larger values of L_* and are less
steep at the faint-end than those of LSB galaxies for limiting B-band local
surface brightness values as faint as mu_B,lim~23-24. Both the LFs and the data
for individual HII regions show that luminous (log L>39 ergs/s) HII regions are
much more common within HSB discs than within LSB discs, implying that the
newly formed star clusters are also larger. Taking this into account along with
the results of Monte Carlo simulations, the shapes of the LFs imply that the
regions within LSB discs and those within the LSB areas of HSB discs are
relatively old (~5 Myr) while the regions within HSB discs for mu_B<24 are
significantly younger (<1 Myr). Since the majority of the LSB galaxies do not
have noticeable spiral arms and the majority of the HSB galaxies do, this may
indicate a transition within HSB discs from spiral arm-driven star formation to
a more locally driven, possibly sporadic form of star formation at mu_B~24, a
transition that does not appear to occur within LSB discs.Comment: Accepted to MNRA
Imaging and Demography of the Host Galaxies of High-Redshift Type Ia Supernovae
We present the results of a study of the host galaxies of high redshift Type
Ia supernovae (SNe Ia). We provide a catalog of 18 hosts of SNe Ia observed
with the Hubble Space Telescope (HST) by the High-z Supernova Search Team
(HZT), including images, scale-lengths, measurements of integrated (Hubble
equivalent) BVRIZ photometry in bands where the galaxies are brighter than m ~
25 mag, and galactocentric distances of the supernovae. We compare the
residuals of SN Ia distance measurements from cosmological fits to measurable
properties of the supernova host galaxies that might be expected to correlate
with variable properties of the progenitor population, such as host galaxy
color and position of the supernova. We find mostly null results; the current
data are generally consistent with no correlations of the distance residuals
with host galaxy properties in the redshift range 0.42 < z < 1.06. Although a
subsample of SN hosts shows a formally significant (3-sigma) correlation
between apparent V-R host color and distance residuals, the correlation is not
consistent with the null results from other host colors probed by our largest
samples. There is also evidence for the same correlations between SN Ia
properties and host type at low redshift and high redshift. These similarities
support the current practice of extrapolating properties of the nearby
population to high redshifts pending more robust detections of any correlations
between distance residuals from cosmological fits and host properties.Comment: 35 pages, 12 figures, 4 tables, accepted for publication in A
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