2,448 research outputs found
The ATLAS^(3D) project – XXIX. The new look of early-type galaxies and surrounding fields disclosed by extremely deep optical images
Galactic archaeology based on star counts is instrumental to reconstruct the past mass assembly of Local Group galaxies. The development of new observing techniques and data reduction, coupled with the use of sensitive large field of view cameras, now allows us to pursue this technique in more distant galaxies exploiting their diffuse low surface brightness (LSB) light. As part of the ATLAS^(3D) project, we have obtained with the MegaCam camera at the Canada–France–Hawaii Telescope extremely deep, multiband images of nearby early-type galaxies (ETGs). We present here a catalogue of 92 galaxies from the ATLAS^(3D) sample, which are located in low- to medium-density environments. The observing strategy and data reduction pipeline, which achieve a gain of several magnitudes in the limiting surface brightness with respect to classical imaging surveys, are presented. The size and depth of the survey are compared to other recent deep imaging projects. The paper highlights the capability of LSB-optimized surveys at detecting new prominent structures that change the apparent morphology of galaxies. The intrinsic limitations of deep imaging observations are also discussed, among those, the contamination of the stellar haloes of galaxies by extended ghost reflections, and the cirrus emission from Galactic dust. The detection and systematic census of fine structures that trace the present and past mass assembly of ETGs are one of the prime goals of the project. We provide specific examples of each type of observed structures – tidal tails, stellar streams and shells – and explain how they were identified and classified. We give an overview of the initial results. The detailed statistical analysis will be presented in future papers
Local Well-posedness for the Kinetic MMT Model
The MMT equation was proposed by Majda, McLaughlin and Tabak as a model to
study wave turbulence. We focus on the kinetic equation associated to this
Hamiltonian system, which is believed to give a way to predict turbulent
spectra. We clarify the formulation of the problem, and we develop the local
well-posedness theory for this equation. Our analysis uncovers a surprising
nonlinear smoothing phenomenon
Optimización de la planta de tratamiento de aguas residuales del municipio de Bojacá-Cundinamarca
Trabajo de InvestigaciónEl trabajo inicialmente habla acerca del problema y la solución que se busca a la PTAR del municipio, luego los objetivos se dan a conocer y los cuales son requisitos para iniciar el proyecto, se realizan una serie de resumenes de articulos de revistas cientificas, tesis de trabajos de grado que aportan a la realización del trabajo para el diseño de la planta, se da inicio con una serie de calculos y especificaciones para cumplir con los objetivos, en las conclusiones se plantean caracteristicas fisico-quimicas que cumplen con la normatividad y por ultimo las recomendaciones que se establecieron de acuerdo a cada estructura que contiene la planta de tratamiento de aguas residuales-Zajòn de oxidaciòn.GLOSARIO
1. INTRODUCCIÓN
2. ANTECEDENTES
3. OBJETIVOS
4. PLANTEAMIENTO Y FORMULACIÓN DEL PROBLEMA
5. METODOLOGÍA
6. MARCO CONCEPTUAL
7. ESTADO DEL ARTE
8. DISEÑO ZANJÓN DE OXIDACIÓN MUNICIPIO DE BOJACÁ
9. CONCLUSIONES
10. RECOMENDACIONES
11. BIBLIOGRAFÍA
ANEXOSPregradoIngeniero Civi
Jet-related Excitation of the [CII] Emission in the Active Galaxy NGC 4258 with SOFIA
We detect widespread [CII]157.7um emission from the inner 5 kpc of the active
galaxy NGC 4258 with the SOFIA integral field spectrometer FIFI-LS. The
emission is found associated with warm H2, distributed along and beyond the end
of southern jet, in a zone known to contain shock-excited optical filaments. It
is also associated with soft X-ray hot-spots, which are the counterparts of the
`anomalous radio arms' of NGC~4258, and a 1 kpc-long filament on the minor axis
of the galaxy which contains young star clusters. Palomar-CWI H-alpha integral
field spectroscopy shows that the filament exhibits non-circular motions within
NGC 4258. Many of the [CII] profiles are very broad, with the highest line
width, 455 km/s, observed at the position of the southern jet bow-shock.
Abnormally high ratios of L([CII])/L(FIR) and L([CII])/L(PAH7.7um) are found
along and beyond the southern jet and in the X-ray hotspots. These are the same
regions that exhibit unusually large intrinsic [CII] line widths. This suggests
that the [CII] traces warm molecular gas in shocks and turbulence associated
with the jet. We estimate that as much as 40% (3.8 x 10^39 erg/s) of the total
[CII] luminosity from the inner 5 kpc of NGC 4258 arises in shocks and
turbulence (< 1% bolometric luminosity from the active nucleus), the rest being
consistent with [CII] excitation associated with star formation. We propose
that the highly-inclined jet is colliding with, and being deflected around,
dense irregularities in a thick disk, leading to significant energy dissipation
over a wide area of the galaxy.Comment: Accepted for Publication in the Astrophysical Journal Oct 29 201
Evidence of boosted 13CO/12CO ratio in early-type galaxies in dense environments
We present observations of CO(1-0) in 17 Combined Array for Research
in Millimeter Astronomy (CARMA) Atlas3D early-type galaxies (ETGs), obtained
simultaneously with CO(1-0) observations. The CO in six ETGs is
sufficiently bright to create images. In these 6 sources, we do not detect any
significant radial gradient in the CO/CO ratio between the
nucleus and the outlying molecular gas. Using the CO channel maps as 3D
masks to stack the CO emission, we are able to detect 15/17 galaxies to
(and 12/17 to at least 5) significance in a spatially
integrated manner. Overall, ETGs show a wide distribution of
CO/CO ratios, but Virgo cluster and group galaxies preferentially
show a CO/CO ratio about 2 times larger than field galaxies,
although this could also be due to a mass dependence, or the CO spatial extent
(). ETGs whose gas has a morphologically-settled
appearance also show boosted CO/CO ratios. We hypothesize that
this variation could be caused by (i) the extra enrichment of gas from
molecular reprocessing occurring in low-mass stars (boosting the abundance of
C to C in the absence of external gas accretion), (ii) much
higher pressure being exerted on the midplane gas (by the intracluster medium)
in the cluster environment than in isolated galaxies, or (iii) all but the
densest molecular gas clumps being stripped as the galaxies fall into the
cluster. Further observations of CO in dense environments, particularly
of spirals, as well as studies of other isotopologues, should be able to
distinguish between these hypotheses.Comment: 13 pages, 3 tables, 7 figures, accepted by MNRA
Beyond the bottom line:redefining the value of design in SME formation
For SMEs to operate in the complex and globalised economic landscape of today engaging with innovation can sustain competitive advantage. Within Design Management, design is being increasingly posited as a strategic resource to facilitate the absorption of new design resources and leverage design knowledge in ways that support SMEs through such economic pressures. Evidencing the relationship between design and economic performance is complex, leading to extensive current research and industry efforts to show how design adds economic value. Despite the value of such efforts, it is important to recognise that innovation means different things to different organizations, especially for start-ups and SMEs. Within the rising tide of design-led innovation, there is a gap being explored in how design can effectively capture and evaluate its contribution within the complex and diverse situations of business development it engages. In seeking to address this gap, this paper presents findings from research undertaken within Design in Action (DiA), an AHRC-funded knowledge exchange hub. Presenting DiA as a single case study, the paper offers methodical reflection on five case example start-up businesses funded by DiA in order to explore the value that design-led innovation approaches offered in their formation
Regional Medical Campuses: A New Classification System
There is burgeoning belief that regional medical campuses (RMCs) are a significant part of the narrative about medical education and the health care workforce in the United States and Canada. Although RMCs are not new, in the recent years of medical education enrollment expansion, they have seen their numbers increase. Class expansion explains the rapid growth of RMCs in the past 10 years, but it does not adequately describe their function. Often, RMCs have missions that differ from their main campus, especially in the areas of rural and community medicine. The absence of an easy-to-use classification system has led to a lack of current research about RMCs as evidenced by the small number of articles in the current literature. The authors describe the process of the Group on Regional Medical Campuses used to develop attributes of a campus separate from the main campus that constitute a “classification” of a campus as an RMC. The system is broken into four models—basic science, clinical, longitudinal, and combined—and is linked to Liaison Committee on Medical Education standards. It is applicable to all schools and can be applied by any medical school dean or medical education researcher. The classification system paves the way for stakeholders to agree on a denominator of RMCs and conduct future research about their impact on medical education
- …