Inflowing gas onto a compact obscured nucleus in Arp 299A: Herschel spectroscopic studies of H2O and OH

Aims. We probe the physical conditions in the core of Arp 299A and try to put constraints to the nature of its nuclear power source. Methods. We used Herschel Space Observatory far-infrared and submillimeter observations of H2O and OH rotational lines in Arp 299A to create a multi-component model of the galaxy. In doing this, we employed a spherically symmetric radiative transfer code. Results. Nine H2O lines in absorption and eight in emission as well as four OH doublets in absorption and one in emission, are detected in Arp 299A. No lines of the 18O isotopologues, which have been seen in compact obscured nuclei of other galaxies, are detected. The absorption in the ground state OH doublet at 119 {\mu}m is found redshifted by ~175 km/s compared to other OH and H2O lines, suggesting a low excitation inflow. We find that at least two components are required in order to account for the excited molecular line spectrum. The inner component has a radius of 20-25 pc, a very high infrared surface brightness (> 3e13 Lsun/kpc^2), warm dust (Td > 90 K), and a large H2 column density (NH2 > 1e24 cm^-2). The outer component is larger (50-100 pc) with slightly cooler dust (70-90 K). In addition, a much more extended inflowing component is required to also account for the OH doublet at 119 {\mu}m. Conclusions. The Compton-thick nature of the core makes it difficult to determine the nature of the buried power source, but the high surface brightness indicates that it is either an active galactic nucleus and/or a dense nuclear starburst. The high OH/H2O ratio in the nucleus indicates that ion-neutral chemistry induced by X-rays or cosmic-rays is important. Finally we find a lower limit to the 16O/18O ratio of 400 in the nuclear region, possibly indicating that the nuclear starburst is in an early evolutionary stage, or that it is fed through a molecular inflow of, at most, solar metallicity.Comment: 14 pages, 13 figures, Accepted for publication in Astronomy and Astrophysic

Modeling the H2O submillimeter emission in extragalactic sources

Recent observational studies have shown that H2O emission at (rest) submillimeter wavelengths is ubiquitous in infrared galaxies, both in the local and in the early Universe, suggestive of far-infrared pumping of H2O by dust in warm regions. In this work, models are presented that show that (i) the highest-lying H2O lines (E_{upper}>400 K) are formed in very warm (T_{dust}>~90 K) regions and require high H2O columns (N_{H2O}>~3x10^{17} cm^{-2}), while lower lying lines can be efficiently excited with T_{dust}~45-75 K and N_{H2O}~(0.5-2)x10^{17} cm^{-2}; (ii) significant collisional excitation of the lowest lying (E_{upper}<200 K) levels, which enhances the overall L_{H2O}-L_{IR} ratios, is identified in sources where the ground-state para-H2O 1_{11}-0_{00} line is detected in emission; (iii) the H2O-to-infrared (8-1000 um) luminosity ratio is expected to decrease with increasing T_{dust} for all lines with E_{upper}<~300 K, as has recently been reported in a sample of LIRGs, but increases with T_{dust} for the highest lying H2O lines (E_{upper}>400 K); (iv) we find theoretical upper limits for L_{H2O}/L_{IR} in warm environments, owing to H2O line saturation; (v) individual models are presented for two very different prototypical galaxies, the Seyfert 2 galaxy NGC 1068 and the nearest ultraluminous infrared galaxy Arp 220, showing that the excited submillimeter H2O emission is dominated by far-infrared pumping in both cases; (vi) the L_{H2O}-L_{IR} correlation previously reported in observational studies indicates depletion or exhaustion time scales, t_{dep}=Sigma_{gas}/Sigma_{SFR}, of <~12 Myr for star-forming sources where lines up to E_{upper}=300 K are detected, in agreement with the values previously found for (U)LIRGs from HCN millimeter emission...Comment: 13 pages, 13 figure

Comment on Reply to Comment of Finger et al. (2013) on: 'Evidence for an Early-Middle Miocene age of the Navidad Formation (central Chile): Paleontological, paleoclimatic and tectonic implications' of Gutiérrez et al. (2013, Andean Geology 40 (1): 66-78)

Indexación: Web of Science; ScieloIn their answer to our Comment (Finger et al., 2013), Le Roux et al. (2013) misunderstand several of our remarks and present what we view as f lawed arguments, principally their case for a shallow-marine environment for part of the Navidad Formation. We do not wish to see this exchange evolve into an endless discussion, but we feel obligated to clarify some points. We think this is necessary because of history and importance of the Navidad Formation as the reference for the marine Miocene of Chile. Here we also expound upon some concepts relevant to the distinction between shallow-and deep-marine environments

DBI equations and holographic DC conductivity

We provide a simple method for writing the Dirac-Born-Infeld (DBI) equations of a Dp-brane in an arbitrary static background whose metric depends only on the holographic radial coordinate z. Using this method we revisit the Karch-O'Bannon's procedure to calculate the DC conductivity in the presence of constant electric and magnetic fields for backgrounds where the boundary is four or three dimensional and satisfies homogeneity and isotropy. We find a frame-independent expression for the DC conductivity tensor. For particular backgrounds we recover previous results on holographic metals and strange metals.Comment: 1+21 pages; v2 : references added, minor typos correcte

Biodiversidad de Psocoptera (Insecta: Psocodea) en México

ResumenLa fauna de Psocoptera de México está constituida por 766 especies, en 105 géneros y 37 familias; el 75% de las especies se distribuye en un “hot spot” de biodiversidad, al sur del paralelo 19° N, entre los meridianos 91°-101° O, en el que se encuentran los estados más ricos en Psocoptera: Chiapas, Oaxaca y Veracruz. Nueve géneros agrupan al 51.1% de las especies y 52 géneros agrupan al 8.6% de las especies. El nivel de endemismo es de 71.9%.AbstractThe psocid fauna of Mexico is constituted by 766 species, in 105 genera and 37 families; 75% of the species occur in a biodiversity hot spot, south of parallel 19° N, between meridians 91°-101° W, in which the richest states for Psocoptera are found: Chiapas, Oaxaca and Veracruz. Nine genera include 51.1% of the species, and 52 genera include 8.6% of the species. The level of endemism is 71.9%

Why Don’t You Play the Game? Evaluating the Use of Gamification in an Undergraduate Finance Course

The board game Monopoly is used as a gamification tool in an undergraduate finance course in a private business school in the Philippines. The use of Monopoly as a gamification tool is evaluated using Han’s (2015) adaptation of the spiral curriculum and Landers\u27s (2015) theory of gamified learning. According to Han, the spiral curriculum “is the circular model best suited to gamification as pedagogy because it allows students to learn and practice basic skills in order to master advanced tasks.” Meanwhile, Landers’s theory of gamified learning posits that “gamification affects learning via moderation when an instructional designer intends to encourage a behavior or attitude that will increase learning outcomes.” In the undergraduate finance course, the Monopoly board game is used as (i) a means to teach basic principles of financial statement analysis and financial forecasting, consistent with the spiral curriculum and (ii) a moderating tool to help influence key attitudes brought about by prior experiences and preconceived notions on the subject, consistent with Landers’s theory of gamified learning. Findings obtained via a qualitative explanatory approach from 101 undergraduate business students suggest that the use of the Monopoly board game is effective as a gamification tool, as seen in students’ ability to proceed to more advanced topics in the finance course and new opinions on finance as expressed at the end of the course. Recommendations for future study include using a control group, conducting studies at the beginning and end of the course, applying quantitative methods, and addressing exogenous factors that may affect the results

A new brachypterous mesepipsocus (psocodea: ’psocoptera’: epipsocidae) from Bolivia

A new species of brachypterous Mesepipsocus, the first species of this genus recorded in Bolivia, is here described and illustrated. It has caeciliusid wing venation, and the gonapophyses lack V1. The type is deposited in the National Collection of Insects, Instituto de Biología, UNAM, México Cit

Nueva especie de lachesilla de la chiquitania boliviana, en el grupo de especies riegeli (PSOCODEA: PSOCOMORPHA: LACHESILLIDAE)

ABSTRACT. A species of Lachesilla in species group Riegeli, fromthe Bolivian Chiquitania, is here described and illustrated. It is the first species in that group to be recorded in Bolivia. It is close to L. paulista García Aldrete, from Argentina and Brazil. An identification key to the males of the species in group Riegeli is included. RESUMEN. Se describe e ilustra una especie de Lachesilla, en el grupo de especies Riegeli, de la Chiquitania Boliviana. Es la primera especie de ese grupo que se registra en Bolivia. Es cercana a L. paulista García Aldrete, de Argentina y Brasil. Se incluye una clave de identificación para los machos de las especies en el grupo Riegeli

Water vapor emission from IRC+10216 and other carbon-rich stars: model predictions and prospects for multitransition observations

We have modeled the emission of H2O rotational lines from the extreme C-rich star IRC+10216. Our treatment of the excitation of H2O emissions takes into account the excitation of H2O both through collisions, and through the pumping of the nu2 and nu3 vibrational states by dust emission and subsequent decay to the ground state. Regardless of the spatial distribution of the water molecules, the H2O 1_{10}-1_{01} line at 557 GHz observed by the Submillimeter Wave Astronomy Satellite (SWAS) is found to be pumped primarily through the absorption of dust-emitted photons at 6 $\mu$m in the nu2 band. As noted by previous authors, the inclusion of radiative pumping lowers the ortho-H2O abundance required to account for the 557 GHz emission, which is found to be (0.5-1)x10^{-7} if the presence of H2O is a consequence of vaporization of orbiting comets or Fischer-Tropsch catalysis. Predictions for other submillimeter H2O lines that can be observed by the Herschel Space Observatory (HSO) are reported. Multitransition HSO observations promise to reveal the spatial distribution of the circumstellar water vapor, discriminating among the several hypotheses that have been proposed for the origin of the H2O vapor in the envelope of IRC+10216. We also show that, for observations with HSO, the H2O 1_{10}-1_{01} 557 GHz line affords the greatest sensitivity in searching for H2O in other C-rich AGB stars.Comment: 35 pages, 12 figures, to be published in The Astrophysical Journa