bluuebunny/crossref_metadata_2025 huggingface dataset:
Square Kilometre Array Station Configuration Using Two-Stage Beamforming
Authors: Jiwani Aziz , Colegate Tim , Razavi-Ghods Nima , Hall Peter J. , Padhi Shantanu , bij de Vaate Jan Geralt
Published: March 2013

The lowest frequency band (70–450 MHz) of the Square Kilometre Array (SKA) will consist of sparse aperture arrays grouped into geographically localised patches or stations. Signals from thousands of antennas in each station will be beamformed to produce station beams which form the inputs for the central correlator. Two-stage beamforming within stations can reduce SKA-low signal processing load and costs, but has not been previously explored for the irregular station layouts now favoured in radio astronomy arrays. This paper illustrates the effects of two-stage beamforming on sidelobes and effective area, for two representative station layouts (regular and irregular gridded tiles on an irregular station). The performance is compared with a single-stage, irregular station. The inner sidelobe levels do not change significantly between layouts, but the more distant sidelobes are affected by the tile layouts; regular tile creates diffuse, but regular, grating lobes. With very sparse arrays, the station effective area is similar between layouts. At lower frequencies, the regular tile significantly reduces effective area, hence sensitivity. The effective area is highest for a two-stage irregular station, but it requires a larger station extent than the other two layouts. Although there are cost benefits for stations with two-stage beamforming, we conclude that more accurate station modelling and SKA-low configuration specifications are required before design finalisation.
Candidate Genes and Voter Turnout: Further Evidence on the Role of 5-HTTLPR
Authors: DEPPE KRISTEN DIANE , STOLTENBERG SCOTT F. , SMITH KEVIN B. , HIBBING JOHN R.
Published: March 2013

Recently in this journal, Charney and English (2012) presented an extensive critique of candidate gene association studies using the widely noted Fowler and Dawes (2008) article on the relationship between self-reported voter turnout and both 5-HTT (serotonin transporter) and MAOA (monoamine oxidase A) as the driving example of their evaluation. Reanalysis of the Fowler and Dawes data by Charney and English, based on four critiques of candidate gene studies, led to the conclusion that neither polymorphism is related to variations in turnout. We add to this empirical debate by conducting an independent test using an original dataset containing 5-HTT data and two separate participation variables: self-reported participation and actual voting records. Our results confirm the original conclusions by Fowler and Dawes on 5-HTT, but also support several of the critiques suggested by Charney and English. We conclude by offering suggestions for the way candidate gene association studies should be interpreted by the discipline and processed by journal editors.
Modeling of electric arcs: A study of the non-convective case with strong coupling
Authors: WRIGHT D. , DELMONT P. , TORRILHON M.
Published: March 2013

In this paper, we investigate a mathematical model for electric arcs. The model is based on the equations of magnetohydrodynamics, where the flow and heat transfer in a plasma is coupled to electrodynamics. Our approach neglects convection and yields a reaction–diffusion model that includes only the core phenomena of electric arcs: Ohmic heating and nonlinear electric conductivity. The equations exhibit interesting mathematical properties like non-unique steady states and instabilities that can be linked to electric arc properties. Additionally, a 3D axisymmetric simulation of the creation and extinction of an electric arc is presented based on a strongly coupled numerical algorithm for the non-convective model. The approach is especially suited for high-current arcs where strong coupling becomes necessary.
The Advance of the Party: Transformation or Takeover of Urban Grassroots Society?
Authors: Thornton Patricia M.
Published: March 2013

While existing scholarship focuses attention on the impact of state control and repression on Chinese civil society, the increasingly independent role of the Communist Party has been largely overlooked. This article reviews the Party's drive to “comprehensively cover” grassroots society over the previous decade against the theoretical debate unfolding among Chinese scholars and Party theoreticians regarding the Party's role with respect to civil society. Focusing on greater Shanghai, frequently cited as a national model of Party-building, I describe the Party's advance and the emergence of Party-organized non-governmental organizations (PONGOs), a new hybrid form of social organization sponsored and supported by local Party committees. I argue that these developments invite a reconsideration of our understandings of the ongoing “associational revolution” and of the Party's relationship to China's flourishing “third realm.”
The Demography of Chinese Nationalism: A Field-Experimental Approach
Authors: Hoffmann Robert , Larner Jeremy
Published: March 2013

Empirical evidence concerning the demographics and development of Chinese nationalism is sparse but important for scholarship and policy. Its collection entails methodological challenges in access and reliability. We conducted a field experiment to measure nationalism in incentive-compatible choices among a diverse group of 447 Chinese subjects in a field setting. Our results demonstrate greater nationalism in female, older, less affluent and more rural respondents. We also find support for nationalism in professional and educated individuals. Our results provide qualified support for a middle-class nationalism in China.
Typing ofSalmonella entericaserovar Infantis isolates from 51 outbreaks in Germany between 1974 and 2009 by a novel phage-typing scheme
Authors: MILLER T. , BRAUN P. G. , FEHLHABER K. , PRAGER R. , PFEIFER Y. , RABSCH W.
Published: March 2013

We developed a new phage-typing method and evaluated its application in combination withXbaI macrorestriction analysis by pulsed-field gel electrophoresis (PFGE) as a useful tool for the long-term epidemiology ofSalmonella entericaserovar Infantis. In this study, we investigated 1008S.Infantis isolates recovered from humans, various animal species and food products from 1973 to 2009. The typing scheme is based on 17 typing phages, defining 61 different patterns within the strain collection. The experiments showed that phage typing is a reliable method for differentiation of outbreaks and sporadic clinical cases as well as for elucidation of chains of transmission. The combined analysis of phage typing and PFGE revealed the existence of epidemic clones with a high stability over time like PT29/XB27 which was identified in nosocomial salmonellosis, community outbreaks as well as in broiler chickens from 2002 to 2009.
Epidemiology of norovirus gastroenteritis in Germany 2001–2009: eight seasons of routine surveillance
Authors: BERNARD H. , HÖHNE M. , NIENDORF S. , ALTMANN D. , STARK K.
Published: March 2013

We analysed data on laboratory or epidemiologically confirmed cases (n = 856 539) and on outbreaks (n = 31 644) notified during week 31 (2001) to week 30 (2009), and performed molecular typing of specimens from 665 outbreaks. We aimed at identifying demographic and molecular characteristics to inform on potential additional approaches to prevent disease spread in the population. The mean incidence by norovirus season (week 31 in one year to week 30 in the following year) was 130 (range 19–300) cases/100 000 population and was highest in persons aged <5 years (430/100 000) and ⩾75 years (593/100 000). The proportion hospitalized in community-acquired cases was 8–19% per season. The mean norovirus-associated mortality was 0·05/100 000 per season and 0·5/100 000 in the ⩾75 years age group. Most outbreaks with known setting (75%) occurred in hospitals (32%), nursing homes (28%), households (24%) and childcare facilities (10%). GII strains dominated in the outbreak specimens. GII.4 strains were found in 82% of nursing home outbreaks, 85% of hospital outbreaks, and 33% of childcare facility and school outbreaks. Cases in younger individuals were notified earlier during the season than adult cases, and outbreaks in childcare facilities and schools preceded those in nursing/residential homes, hospitals and private households. We suggest future studies to investigate more closely potential transmission patterns between children and adults.
Holy Shroud Exhibition 2010: Health Services During a 40-Day Mass-Gathering Event
Authors: Bortolin Michelangelo , Ulla Marco , Bono Alessia , Ferreri Enrico , Tomatis Mariano , Sgambetterra Sergio
Published: March 2013

Introduction

Mass-gathering events require varying types and amounts of medical resources to deal with patient presentations as well as careful planning for environmental health management. The Holy Shroud Exhibition was hosted in Torino, Italy, between April and May 2010. The venue was a unique mass-gathering event which lasted several weeks. It was held in a limited area in the center of the city and it was attended by a large and heterogeneous population. A dedicated Health Care Service was created for the event.

Methods

This study is a retrospective analysis of clinical presentations of patients who were managed by the Medical Services during the event. The main study outcomes included Patient Presentation Rate (PPR), type of injuries and illnesses, and the Transport to Hospital Rate (TTHR).

Results

The PPR and TTHR were both low (0.27 and 0.039 respectively). The majority of patients presented with low severity codes and no sudden cardiac death (SCD) or cardiac arrest occurred. Cardiac and trauma emergencies were most frequent categories of presentation. A number of pediatric patients (19.37%) were treated by the event Medical Service. Approximately two million persons participated in the 40-day event.

Conclusion

The experience for this 40-day event supported having an on-site, organized, dedicated Medical Service that decreased overcrowding of the local Emergency Medical System and hospitals. It is recommended that, for such events, there be recruitment of emergency physicians with experience in mass-gathering events, recruitment of pediatricians, and training for professionals during the planning process.

BortolinM, UllaM, BonoA, FerreriE, TomatisM, SgambetterraS. Holy Shroud Exhibition 2010: health services during a 40-day mass-gathering event. Prehosp Disaster Med. 2013;28(3):1-6.
The Active Therapeutic Processes of Acceptance and Commitment Therapy for Persistent Symptoms of Psychosis: Clients’ Perspectives
Authors: Bacon Tory , Farhall John , Fossey Ellie
Published: March 2013

Background:There is limited research on the applicability and effectiveness of Acceptance and Commitment Therapy (ACT) for people experiencing psychotic disorders. Clinical trials suggest ACT may be efficacious in reducing distress and rehospitalization rates in psychosis. Mindfulness and reduced literal believability of thought content have been associated with reduced distress for this population.Aims:To better understand ACT for psychosis, this study investigated clients’ perspectives of the hypothesized active therapeutic processes of ACT.Method:Semi‑structured interviews, conducted with nine adults diagnosed with schizophrenia or schizoaffective disorder and persistent positive symptoms, were analysed thematically.Results:Four themes emerged: Usefulness of therapy; Changes attributed to ACT; Understanding of therapy; and Non-specific therapy factors. All participants found therapy useful and recommended ACT. Mindfulness, defusion, acceptance and values work were described as the most useful therapy components and contributing to positive changes. Self-rated frequency of symptoms did not change; however a reduction in the intensity and distress associated with symptoms was reported. Non-specific therapy factors were deemed useful by participants but not directly related to outcome.Conclusions:These findings are consistent with the theoretically defined underlying active processes of ACT and are relevant for this population. The findings also indicate important clinical implications for ACT for this client group: greater attention to the client connecting metaphors and concepts to the intended meaning may be valuable; caution should be used with some mindfulness and defusion techniques for intense experiences; and values work may be particularly useful for this population.
Food security and development in South Sudan: a call to action
Authors: Tappis Hannah , Doocy Shannon , Paul Amy , Funna Sonya
Published: March 2013

Objective

To examine household food insecurity and coping mechanisms in two relatively politically stable states of South Sudan.

Design

Cross-sectional assessment including structured interviews and focus group discussions with food aid programme beneficiaries and staff. Structured interview findings were analysed with descriptive statistics using the statistical software package STATA version 11.

Setting

Rural households in four payams (sub-county administrative districts) benefiting from a multi-year assistance programme funded by the US Agency for International Development. The study was conducted in January 2012, six months after independence.

Subjects

Study subjects included eighty mothers of children aged 6–23 months in structured interviews and eight focus groups, each with six to ten participants, of mothers of children aged 6–23 months.

Results

Ninety-three per cent of households surveyed in Warrap and 100 % of households in Northern Bahr el Ghazal states were severely food access insecure. Nearly all households (97·5 %) surveyed in both states reported there were months in 2011 without enough food to eat. The majority of households (88 %) reported sometimes or often going to bed hungry in the month preceding the study. A number of coping mechanisms were used when households did not have enough food, including reduced meal size, skipping meals, selling assets and engaging in some kind business in order to generate money to buy food.

Conclusions

Given the highly volatile political, economic and humanitarian situation in South Sudan, the priorities of the international community are understandably focused on securing greater stability in South Sudan and preventing humanitarian needs from escalating significantly. There is a need, however, for simultaneous emphasis on food assistance and longer-term development strategies throughout South Sudan, particularly in areas of agriculture, livelihoods and food security.
GMC Origins and Turbulent Motions in Spiral and Dwarf Galaxies
Authors: Elmegreen Bruce G.
Published: March 2013

CO clouds can be non-self-gravitating in high pressure environments, while most should be strongly self-gravitating at low metallicities and ambient pressures. In the LMC, which is HI-rich, GMC formation and destruction should generally include molecule formation and destruction. In M51, which is CO-rich, GMCs grow by coalescence. The Milky Way is between these two situations. In all cases, large clouds form by accretion of gas and smaller clouds independently of the presence of molecules. GMCs in the Milky Way are analogous to dust lanes and spurs in other galaxies. The virial parameter α usually decreases monotonically with increasing cloud mass in surveys, which implies that small scale structure is formed by turbulence. Hierarchies of sequences with decreasing α should be present in cloud complexes from sub-solar masses up to the ambient Jeans mass (107M⊙).
Deuterium Fractionation and Ionization Degree in Massive Protostellar/cluster Cores
Authors: Chen Huei-Ru , Liu Sheng-Yuan , Su Yu-Nung
Published: March 2013

We have conducted a survey of deuterium fractionation of N2H+, RD(N2H+) ≡ N(N2D+)/N(N2H+), with the Arizona Radio Observatory (ARO) Submillimeter Telescope (SMT) to assess the use of RD(N2H+) as an evolutionary tracer among massive protostellar/cluster cores in early stages. Our sample includes 32 dense cores in various evolutionary stages, from high-mass starless cores (HMSCs), high-mass protostellar objects (HMPOs), to ultra-compact (UC) HII regions, in infrared dark clouds (IRDCs) and high infrared extinction clouds. The results show a decreasing trend in deuterium fractionation with evolutionary stage traced by gas temperature and line width (Fig. 1). A moderate increasing trend of deuterium fractionation with the CO depletion factor is also found among cores in IRDCs and HMSCs. These suggest a general chemical behavior of deuterated species in low- and high-mass protostellar candidates. Upper limits to the ionization degree are also estimated to be in the range of 4 × 10−8 − 5 × 10−6.
Molecular Gas Around the Infrared Dust Bubbles
Authors: Gong Yan , Mao Ruiqing , Fang Min , Sun Jixian , Lu Dengrong
Published: March 2013

We have conducted a mapping survey toward a sample of 17 infrared dust bubbles in three 3 mm waveband CO isotopic lines simultaneously. Such bubbles are candidates to search for triggered massive star formation. We present the data and report preliminary results.
VLBI Observations and NH3 Mapping of the Star-forming Region NGC2264
Authors: Kamezaki Tatsuya , Imura Kenji , Nagayama Takumi , Omodaka Toshihiro , Handa Toshihiro , Yamaguchi Yoshiyuki , Chibueze James O. , Sunada Kazuyoshi , Nakano Makoto
Published: March 2013

We have measured the annual parallax of the water maser source associated with star forming region NGC2264 from observations with VLBI Exploration of Radio Astrometry (VERA). We detected masers at VLSR = 7.2 km s−1. We discussed its driving sources of detected maser spots. One of the maser spots was associated with a centimeter continuum source observed with VLA. Neither optical, infrared nor X-ray sources is catalogued near the spot. The other maser spot is located close to an X-ray source, although there is no optical or infrared counterpart. The proper motion of the former spot was (μα, μδ) = (23.91 ± 4.29, −29.81 ± 4.27) and the proper motion of latter spot was (μα, μδ) = (−0.96 ± 0.58, −6.05 ± 3.06). For the latter spot, the peculiar motion is ∼ 150 km s−1 and it has the high velocity and this may be a jet or an outflow from a young star. The observed parallax is 1.365 ± 0.098 mas, corresponding to the distance of 738+57−50 pc. This value is constant with the photometric distance of NGC2264 previously measured. The fitting result of the parallax is shown in figure 1. We also observed in NH3 (1,1), (2,2), (3,3) lines of NGC2264 with the Kashima 34m telescope. We estimated the star formation efficiency (SFE) of NGC2264 from the dense molecular mass of NH3 and the stellar mass calculated by Teixeira et al. (2012). The SFE is 9 – 12% which is consistent with previous results.
Molecular gas and triggered star formation surrounding Wolf-Rayet stars
Authors: Liu Tie , Wu Yuefang , Zhang Huawei
Published: March 2013

The environments surrounding nine Wolf-Rayet stars were studied in molecular emission. Expanding shells were detected surrounding these WR stars (see left panels of Figure 1). The average masses and radii of the molecular cores surrounding these WR stars anti-correlate with the WR stellar wind velocities (middle panels of Figure 1), indicating the WR stars has great impact on their environments. The number density of Young Stellar Objects (YSOs) is enhanced in the molecular shells at ∼5 arcmin from the central WR star (lower-right panel of Figure 1). Through detailed studies of the molecular shells and YSOs, we find strong evidences of triggered star formation in the fragmented molecular shells (Liu et al. 2010).
Evolution of HII Regions around Massive YSOs
Authors: Stephens Ian W. , Looney Leslie W. , Indebetouw Remy , Chu You-Hua , Gruendl Robert A. , Chen C.-H. Rosie , Seale Jonathan P. , Evans Jessica Marie
Published: March 2013

We survey HII free-free emission around ∼60 spectroscopically confirmed young stellar objects (YSOs) in the Large Magellanic Cloud using the Australia Telescope Compact Array (ATCA) at 3.3 and 5.5 cm. From each YSOs' infrared spectrum, we: a) quantify how embedded/evolved the YSO is through principle component analysis (PCA) of the silicate absorption (Seale et al. 2009); and b) estimate the mass from SED models (Robitaille et al. 2007). We have four main results: (1) Based on mass estimates from SED models and ATCA detection limits, we find that most massive YSOs are in HII regions regardless of age; (2) Older massive YSOs (as indicated by silicate PCA index) are much more likely to be resolved than younger YSOs, indicating evolving HII regions; (3) Resolved (typically older) sources usually have lower densities. Thus, in our survey we see a transition from ultra-compact HII to HII regions; and (4) We find that accretion about the massive YSO is likely non-spherical, resulting in HII regions in the shape of prolate spheroids.
AMANOGAWA-2SB survey: a northern galactic plane survey in 12CO (J = 2 − 1) and 13CO (J = 2 − 1) with the Amanogawa telescope
Authors: Handa Toshihiro , Yoda Takahiro , Kohno Kotaro , Nakajima Taku , Morino Jun-ichi , Yonekura Yoshinori , Ogawa Hideo , Kimura Kimihiro , Dobashi Kazuhiro
Published: March 2013

We performed 12CO(J = 2 − 1) and 13CO(J = 2 − 1) line surveys of the galactic plane using the AMANOGAWA telescope (Nakajima et al. 2007) which covers 5° ≤ l ≤ 180° on a 7'.5 grid. The telescope beamsize and velocity resolution are 8.7′ ± 0.4′ and 1.3 km s−1. The resultant rms noise level is typically 0.12 K in TA*. We found a linear correlation between 12CO(J = 2 − 1) and 12CO(J = 1 − 0) and a curved correlation between 12CO(J = 2 − 1) and 13CO (J = 2 − 1), although the intensity ratios of these three lines have intrinsic variation. These correlations can be reproduced with simple radiative transfer equations suggesting some restrictions on the physical quantities of molecular gas on a galactic scale.
The disk targets for LAMOST pilot survey
Authors: Hou J. L. , Zhong J. , Chen L. , Yu J. C. , Liu C. , Deng L. C.
Published: March 2013

LAMOST has 4 meters in diameter with 4000 fibers in the focal plane. The telescope is now on the way towards full spectroscopy survey periods. This survey project has the potential to largely increase our understanding of the substructure of the Galactic stellar spheroid and different disk components through accurate measurements of radial velocities, metallicities and effective temperatures of millions of stars.
The spiral structure of our Milky Way
Authors: Hou L. G. , Han J. L.
Published: March 2013

The spiral structure of our Milky Way has not yet been well outlined. HII regions, giant molecular clouds (GMCs) and 6.7-GHz methanol masers are primary tracers for spiral arms. We collect and update the database of these tracers which has been used in Hou et al. (2009) for the spiral arms.

The new database consists of ∼ 2000 HII regions, ∼ 1300 GMCs and ∼ 800 methanol masers (6.7 GHz). If the photometric or trigonometric distance for any tracer is available from the literature, we will adopt it. Otherwise, we have to use the kinematic distance. We modify the VLSR according to the newly determined solar motions (U0 = 10.27 km s−1, V0 = 15.32 km s−1 and W0 = 7.74 km s−1, Schönrich et al. 2010), then calculate the kinematic distances with a flat rotation curve (R0 = 8.3 kpc, θ0 = 239 km s−1, Brunthaler et al. 2011). Very important step is that we weight tracers according to the excitation parameters of HII regions or the masses of GMCs, and a constant weight for masers. All three kinds of tracers are used together to outline the spiral structure (Fig. 1). A contour and gray map is constructed after we made a Gaussian extension for the tracers with the amplitude of weighting parameter.
H2CO Observations Towards CH3OH Maser Sources
Authors: Okoh Daniel , Esimbek Jarken , Zhou JianJun , Tang Xindi , Chukwude Augustine , Urama Johnson , Okeke Pius
Published: March 2013

Formaldehyde (H2CO) is an accurate probe of physical conditions in dense and low-temperature molecular clouds towards massive star formation regions, while 6.7 GHz methanol (CH3OH) masers provide ideal sites to probe the earliest stages of massive stellar formation. We present preliminary results of our investigation into the possible relationship between formaldehyde and methanol astrophysical masers with the view to expanding knowledge on massive star formation processes. Observations are done using the Nanshan 25m radio telescope of the Xinjiang Astronomical Observatories, Urumqi, China. 127 Methanol sources (from the work of Green et al. 2010, Xu et al. 2003, Pestalozzi et al. 2005, and Xu et al. 2009) have been observed so far for 4.8 GHz formaldehyde absorption lines, and H2CO signals have been detected in 86 of them, 31 of which are newly discovered. We obtained good correlation (0.85 correlation coefficient) between the velocities of the sources, and a poor correlation (−0.03 correlation coefficient) between their intensities, an indication that signals from the two lines originate from about the same region, but that the excitation mechanisms that drive them are likely different.
The ISM of Low Metallicity Galaxies: The Herschel view
Authors: Madden Suzanne C. , Rémy Aurélie , Galliano Frédéric , Galametz Maud , Bendo George , Cormier Diane , Lebouteiller Vianney , Hony Sacha ,   Herschel SAG 2 consortium
Published: March 2013

The wide variety of low metallicity galaxies of the local universe serve as convenient laboratories to study the evolution of gas and dust and conditions for star formation in environments which may resemble those of the early universe. The Herschel Dwarf Galaxy Survey is studying the far infrared (FIR) and submillimeter (submm) properties of the gas and dust in galaxies with metallicity values as low as 1/45 that of solar. With complementary Spitzer, Laboca/APEX, Scuba/JCMT data, the dust spectral energy distributions are well constrained now, providing more accurate dust masses. We find a steep drop in dust-to-gas mass ratio (D/G) when the metallicity is below 12+log(O/H) ∼ 8. A submillimeter excess can be found in some low metallicity galaxies, which, when present, becomes apparent at wavelengths at or longer than 500 μm. While CO is difficult to observe in low metallicity gas, the FIR fine structure lines, on the other hand, are very luminous and highlight a potentially important reservoir of CO-free molecular gas, better traced by the 158 μm [CII] line.
Molecular Gas and Dust in Nearby Galactic Centers: from SMA to ALMA
Authors: Sakamoto Kazushi
Published: March 2013

SMA observations of molecular gas and dust in nearby galactic centers are presented to showcase remarkable ISM properties including warm to very hot gas, molecular clouds producing massive star clusters, and mechanical feedback through bubbles and outflows.
Statistical Properties of Highly Luminous HII Regions in the Interacting Zone of the Antennae Galaxies, and Comparison with the Molecular Cloud Component
Authors: Font Joan , Beckman John E. , Zaragoza Javier , Erroz-Ferrer Santi , Garcia-Lorenzo Begoña
Published: March 2013

We have used the package CLOUDPROPS (Rosolowsky & Leroy 2008) in order to identify clouds, which are contained in data cubes of molecular/Hα line emission, and extract their properties. The molecular data cube is taken from the ALMA public archive and the ionized hydrogen data cube was obtained with the Fabry-Perot interferometer, GHαFaS, on the 4.2 m WHT in La Palma. In our study of the overlap region of the Antennae galaxies we have identified two populations of molecular clouds, above and below log M/M⊙ = 6.75 (in agreement with Wei et al. 2012 who find the break in mass at log M/M⊙ = 6.5) and two different populations of ionized gas clouds; the break in the luminosity occurs near log L = 37.6 (see Fig. 1). We have measured the masses, velocity dispersions and luminosities of the clouds, and derived relation between them for each population. Population II clouds (both molecular and ionized) tend to be located in the most luminous regions, while population I clouds can be found in the outskirts. This work will be published in Font et al. (2013).
Revealing the Physical Properties of GMC Complexes in the Spiral Arms of NGC 6946
Authors: Topal Selçuk , Bayet Estelle , Bureau Martin , Walsh Wilfred , Davis Timothy A.
Published: March 2013

In this study, we probe for the first time the molecular gas physical properties of several star forming regions located in the arms and inter-arms of the spiral galaxy NGC 6946. Combining our observations with additional data found in the literature, we provide in this study the most complete CO ladder ever obtained in these inter-arm and arm regions, i.e. the CO(1-0, 2-1, 3-2, 4-3, 6-5) and 13CO(1-0, 2-1) transitions. For each region studied, we use more precisely the large velocity gradient (LVG) assumption in order to derive the beam-averaged molecular gas physical properties. Namely, we obtained the gas kinetic temperature (i.e. 'best' TK), volume number gas density (i.e. 'best' n(H2)) and CO column density (i.e. 'best' N(CO)) which best reproduce the data for 8 regions investigated. Optical depths were also estimated for a large variety of CO lines in these regions. To identify the best values found, we used two complementary theoretical approaches when comparing the model predictions with the observations, i.e. the χ2 minimisation and the likelihood. Very different physical conditions for the molecular gas from a region to another have been obtained: TK ranges from 10 to 250 K, n(H2) ranges from 102.3 to 107.0 cm−3 and N(CO) ranges from 1015.0 to 1019.3 cm−2 among the arm and inter-arm regions. For each region probed, we also published for the first time the CO spectral line energy distribution (SLED) from CO(1-0) to CO(10-9) for this galaxy, mixing observations and model predictions which provide an essential insight for future follow-up observational programmes. Finally, in this work, we discuss the physical properties we obtained for each region in relation with the presence of young stellar population characteristics such as supernovae remnants (SNRs), Hi holes, Hii regions.
Expanding the Horizon of Molecular Gas Surveys of Nearby Galaxies
Authors: Wang Zhong , Jiang Xuejian , Watson Linda
Published: March 2013

This contribution discusses the prospect of using millimeter interferometry to survey molecular gas in a large number of galaxies beyond the distance of Virgo.
Brightest Cluster Galaxies & Cooling Flows
Authors: Salomé Philippe
Published: March 2013

In the absence of any form of feedback heating, the gas in the central regions of massive relaxed cluster should cool and initiate a cooling flow. The presence/efficiency of an additional heating and the ultimate fate of the cooling gas is the subject of an extensive debate. In the last decade, molecular and atomic gas have been found in many Brightest Cluster Galaxies. I will review these observational results and discuss their implication for galaxy formation/evolution, in the perspective of ALMA.
Probing the cool ISM in galaxies via 21 cm H i absorption
Authors: Allison J. R. , Sadler E. M. , Curran S. J. , Reeves S. N.
Published: March 2013

Recent targeted studies of associated H i absorption in radio galaxies are starting to map out the location, and potential cosmological evolution, of the cold gas in the host galaxies of Active Galactic Nuclei (AGN). The observed 21 cm absorption profiles often show two distinct spectral-line components: narrow, deep lines arising from cold gas in the extended disc of the galaxy, and broad, shallow lines from cold gas close to the AGN (e.g. Morganti et al. 2011). Here, we present results from a targeted search for associated H i absorption in the youngest and most recently-triggered radio AGN in the local universe (Allison et al. 2012b). So far, by using the recently commissioned Australia Telescope Compact Array Broadband Backend (CABB; Wilson et al. 2011), we have detected two new absorbers and one previously-known system. While two of these show both a broad, shallow component and a narrow, deep component (see Fig. 1), one of the new detections has only a single broad, shallow component. Interestingly, the host galaxies of the first two detections are classified as gas-rich spirals, while the latter is an early-type galaxy. These detections were obtained using a spectral-line finding method, based on Bayesian inference, developed for future large-scale absorption surveys (Allison et al. 2012a).
Shards of SHARDS: emission line galaxies
Authors: Cava Antonio , Villar Víctor , Pérez-González Pablo G. ,   the SHARDS Team
Published: March 2013

SHARDS (Survey for High-z Absorption Red & Dead Sources; see Pérez-González et al. 2012) is an optical ultra-deep spectro-photometric survey with OSIRIS-GTC aimed at selecting and studying massive passively evolving galaxies at z=1.0–2.3 in GOODS-North. Nonetheless, the data quality allow a plethora of studies on galaxy populations, including Emission Line Galaxies (ELGs) about which we have started our first science verification project. The selection procedure, measurement and first analysis of ELGs in SHARDS, demonstrate the huge capability of the survey in providing physical information for a large sample of emitters, spanning from local Hα to high-z Lyman-α emitters.
Morphologies and Substructures of UV Star-Forming Galaxies at Intermediate-z
Authors: Voyer E. N. , de Mello D. F. , Blevins S. M. , Teplitz H. I. , Gardner J. P. , Siana B. D. , Soto E.
Published: March 2013

Exploring potential links between the internal physical processes of galaxies with respect to their external morphologies can reveal connections between past and present populations. One primary physical driver of galaxy evolution is star formation, which is directly detected from UV emission. Here, we summarize a study investigating the optical and UV morphologies of rest-frame UV-detected star-forming galaxies at intermediate redshifts (0.1<z<1.2) observed with the Hubble Space Telescope (HST) Solar Blind Channel (far-UV) and Wide Field PlanetaryCamera 2 (WFPC2; U-band) in the Great Observatories Origins Deep Survey fields.
The molecular gas in Luminous Infrared Galaxies: a new emergent picture
Authors: Papadopoulos Padelis P. , Zhang Zhi-Yu , Weiss Axel , van der Werf Paul , Isaak Kate , Gao Yu , Xilouris Manolis , Greve Thomas R.
Published: March 2013

Results from a large, multi-J CO, 13CO, and HCN line survey of Luminous Infrared Galaxies (LIRGs: LIR≥ 1010 L⊙) in the local Universe (z≤0.1), complemented by CO J=4–3 up to J=13–12 observations from the Herschel Space Observatory (HSO), paints a new picture for the average conditions of the molecular gas of the most luminous of these galaxies with turbulence and/or large cosmic ray (CR) energy densities UCR rather than far-UV/optical photons from star-forming sites as the dominant heating sources. Especially in ULIRGs (LIR>1012 L⊙) the Photon Dominated Regions (PDRs) can encompass at most a few % of their molecular gas mass while the large UCR∼ 103 UCR, Galaxy, and the strong turbulence in these merger/starbursts, can volumetrically heat much of their molecular gas to Tkin∼ (100-200) K, unhindered by the high dust extinctions. Moreover the strong supersonic turbulence in ULIRGs relocates much of their molecular gas at much higher average densities (≥104 cm−3) than in isolated spirals (∼ 102–103 cm−3). This renders low-J CO lines incapable of constraining the properties of the bulk of the molecular gas in ULIRGs, with substantial and systematic underestimates of its mass possible when only such lines are used. Finally a comparative study of multi-J HCN lines and CO SLEDs from J=1–0 up to J=13–12 of NGC 6240 and Arp 193 offers a clear example of two merger/starbursts whose similar low-J CO SLEDs, and LIR/LCO,1−0 and LHCN, 1−0/LCO,1-0 ratios (proxies of the so-called SF efficiency and dense gas mass fraction), yield no indications about their strongly diverging CO SLEDs beyond J=4–3, and ultimately the different physical conditions in their molecular ISM. The much larger sensitivity of ALMA and its excellent site in the Atacama desert now allows the observations necessary to assess the dominant energy sources of the molecular gas and its mass in LIRGs without depending on the low-J CO lines.
Molecular richness of the diffuse interstellar medium: a signpost of turbulent dissipation
Authors: Falgarone Edith , Godard Benjamin , des Forêts Guillaume Pineau , Gerin Maryvonne
Published: March 2013

The Herschel/HIFI absorption spectroscopy surveys reveal the unexpected molecular richness of the Galactic diffuse ISM, even in gas of very low average H2 molecular fraction. In particular, two hydrides, CH+ and SH+ with highly endoergic formation routes have abundances that challenge models of UV-driven chemistry. The intermittent dissipation of turbulence appears as a plausible additional source of energy for the diffuse ISM chemistry. We present recent results of the so-called models of Turbulent Dissipation Regions (TDR). The abundances of many of the molecules observed in the diffuse ISM, including CO that is used as a tracer of the molecular cloud mass, may be understood in the framework of the TDR models.
Densitometry of Active Star Forming Galaxies
Authors: Henkel C. , Mangum J. G. , Darling J. , Menten K. M.
Published: March 2013

Attempting to distangle density and kinetic temperature of the star forming molecular gas in the central regions of galaxies, we have embarked on a project involving sensitive measurements of a variety of formaldehyde (H2CO) and ammonia (NH3) transitions. Preliminary results, based on observations from the Green Bank Telescope (GBT) and the Very Large Array (VLA) are summarized and an outline for the entire project is given.
Quantum IR line list of NH3 and isotopologues for ISM and dwarf studies
Authors: Huang Xinchuan , Schwenke David W. , Lee Timothy J. , Sung Keeyoon , Brown Linda R.
Published: March 2013

Ammonia (NH3) was the first polyatomic molecule observed in the ISM. Its importance in interstellar molecules is only second to CO because its rovibrational spectroscopic signature can be used very effectively at deducing the conditions of the interstellar environment such as temperature and density, and because it is found in so many different interstellar objects in a wide temperature range. However, experimental determination of NH3 IR spectra is extremely difficult due to the large-amplutide inversion vibration, and the existing HITRAN2008 database for NH3 is limited in temperature, coverage, completeness, and accuracy. With rapid progress in theoretical chemistry and computational resources, now we are able to generate a highly reliable/accurate IR line list of NH3 (and its isotopologues) for astronomical studies. Exact quantum rovibrational computations on an empirically refined potential energy surface (with nonadiabatic corrections included) have achieved accuracies of 0.02-0.05 cm−1 (for line position) and better than 85-95% (for line intensity) for both NH3 and 15NH3 spectra. The unique feature of our work is that our predictions are essentially as accurate as reproducing existing measurements, suitable for synthetic simulation of various astrophysical environments or objects. The reliabilty and accuracy of our predictions for missing bands and higher energies computed on HSL-2 (Fig. 1) have been proved by the most recent high-resolution experiments and extended up to 7000 cm−1. See Huang et al. 2008, Huang et al. 2011, & Sung et al. 2012 for more details.
Molecular Cores in Taurus: Evolution and Dynamics
Authors: Qian Lei , Li Di , Goldsmith Paul
Published: March 2013

The evolution and dynamics of the molecular cores traced by 13CO J = 1 → 0 emission in the Taurus molecular cloud are studied. We performed a systematic examination of the distribution and dynamic state of cores in a large contiguous region, as well as the core ages, which lie between 106 and 107 years. The core velocity dispersion (CVD), which is the variance of the core velocity difference δ v, exhibits a power-law behavior as a function of the apparent separation L, i.e. CVD (km/s) ∝ L (pc)0.7, with similarities to Larson's law for the velocity dispersion of the gas.
Spatial Variation of CO Excitation in High-z Galaxies
Authors: Sharon Chelsea E. , Baker Andrew J. , Harris Andrew I. , Lutz Dieter , Tacconi Linda J.
Published: March 2013

Previous studies of the molecular gas excitation in high-redshift galaxies have focused on galaxy-wide averages of CO line ratios. However, it is possible that these averages hide spatial variation on sub-galactic scales, disguising the true distribution and conditions of the molecular gas within star-forming galaxies. Even in the pre-ALMA era we have begun to see evidence for spatial variation of CO excitation in both rest-UV selected and submillimeter-selected galaxies at z > 2, aided both by the increased frequency coverage of the Jansky Very Large Array (allowing high-resolution observations of the CO(1–0) line, the best tracer for the coldest molecular gas) and by the benefits of gravitational lensing for spatially extended sources. We show new results for multiple high-redshift systems that reveal spatial and/or spectral variations in CO excitation, including an early-stage merger that has different conditions in its two components, thereby illustrating the need for high spatial and spectral resolution mapping in order to accurately characterize the molecular ISM in high-z galaxies.
Rotationally Excited H2 in the Magellanic Clouds
Authors: Xue Rui , Welty Daniel , Wong Tony
Published: March 2013

We have performed a survey study of rotational excited-state H2 Lyman-Werner absorption lines in the entire FUSE Magellanic Clouds Legacy archive. These lines reflect the UV pumping and formation conditions of H2, enabling a more comprehensive study of H2 gas properties, e.g. J-level populations N(J) and b-values (generally indicating the velocity dispersion). Combining with our previous measurements of N(Hi) and N(H2), we derived H2 excitation temperatures, gas volume density n(H), and local UV radiation field strength IUV for each sight line. The results indicate a weaker correlation between n(H) and IUV in Magellanic Clouds than the Galactic sight lines. We also obtained N(H)/E(B − V) ratios from the Spitzer-SAGE and previous CO J = 1 − 0 / Hi 21 cm surveys at sight line locations, using dust modeling and standard line brightness-column density conversion factors. They show a roughly linear correlation with absorption-based N(H)/E(B − V) values, and have a similar scatter (∼0.7 dex) across the LMC and SMC.
ISM Diagnostics: Dust
Authors: Onaka Takashi
Published: March 2013

Infrared (IR) observations provide significant information on the lifecycle of dust grains in the interstellar medium (ISM), which is crucial for the understanding of the evolution of matter in the universe. The IR spectral energy distribution (SED) of the dust emission tells us the relative abundance of sub-micron grains, very small grains, and carriers of the unidentified infrared (UIR) emission bands, since they emit the far-IR, the mid-IR, and the UIR bands from the near- to mid-IR, respectively. On the other hand, the UIR emission bands themselves offer a useful means to probe the physical conditions from which the band emission arises because each band is assigned to a specific C-H or C-C vibration mode and because its relative intensity should reflect the properties of the band carriers and the physical conditions of the environment. Here the two diagnostic methods using IR observations are briefly described together with examples of the observational results. Implications for the dust lifecycle are also discussed.
Processing of Interstellar Dust Grains in Galaxies Revealed by AKARI
Authors: Kaneda Hidehiro , Ishihara Daisuke , Kobata Koudai , Kondo Toru , Yamagishi Mitsuyoshi , Yasuda Akiko , Onaka Takashi , Sakon Itsuki , Suzuki Toyoaki
Published: March 2013

With AKARI, we have performed a systematic study of interstellar dust grains in various environments of galaxies. In many cases, the IR emission of dust is an important tool to trace star-forming activities in galaxies. However it is much more than just star-formation tracers. AKARI has revealed the detailed properties of dust grains in regions not relevant to star formation as well, some of which are found not to follow our old empirical knowledge. Because of its unique capabilities, such as near- and far-IR spectroscopy, and all-sky coverage, AKARI has provided new knowledge on the processing of carbonaceous grains including polycyclic aromatic hydrocarbons. We present the latest results obtained from our AKARI observations of the ISM in our Galaxy and nearby galaxies.
The rapid evolution of dust content in galaxies over the last five billion years
Authors: Gomez H. L. , Dunne L. , Smith D. J. B. , da Cunha E.
Published: March 2013

The Herschel-ATLAS (H-ATLAS) will provide an unrivalled sample of galaxies, probing the normal star-forming submillimetre population of galaxies for the first time. Here, we exploit the Science Demonstration Phase (SDP) data to model the evolution of the interstellar content of galaxies in recent history. The most massive H-ATLAS galaxies show a large increase in the dust content five billion years ago compared to the present epoch. These observations are difficult to explain using standard dust models, one possibility could be contributions from a non-stellar source of dust e.g. grain growth in dense clouds; this would imply that less than 10% of dust would be condensed in stellar atmospheres. Alternatively, an initial mass function which becomes top heavy at high star formation rate densities could also explain this discrepancy.
Evolution of ISM Contents of Massive Galaxies from z = 2 to 0.3
Authors: Scoville Nick
Published: March 2013

The mass of ISM in high redshift Galaxies is a major determinant of their morphology, star formation activity and how they will evolve to low redshift. Measurement of the CO lines at z > 0.5 are time consuming, even with the sensitivity of ALMA, and the derived ISM masses are subject to uncertainty in the CO-to-H2 conversion factor. Here I describe a much faster technique— measuring the long wavelength Rayleigh-Jeans dust emission using the spectacular continuum sensitivity of ALMA. Using a metallicity-dependent gas-to-dust abundance ratio derived from studies of low-z galaxies, one then obtains the ISM mass. Initial results from our ALMA Cycle-0 observations are presented for a small sample of stellar-mass selected galaxies in COSMOS. This technique will enable measurement of 100's of galaxies at high-z with observations of typically ∼10 min per galaxy.
Gas and attenuation in galaxies
Authors: Boquien Médéric , Boselli Alessandro , Buat Véronique
Published: March 2013

To determine the spectral energy distribution of galaxies in large numerical simulations, proper treatment of the attenuation is crucial. One of the most common methods in semi–analytic models is to compute the attenuation from the gas surface density. The aim of the present study is to provide new but still simple relations between the gas surface density and the optical depth, directly calibrated on galaxies. To do so we combine multi–wavelength data and perform a pixel–by–pixel analysis on a sample of nearby galaxies. Examination of the influence of these new relations on simulated FUV and IR luminosity functions shows a clear impact compared to older oft–used relations, which in turn could affect the conclusions drawn from studies based on large scale cosmological simulations.
Analysis of the Interstellar Medium Properties of the Herschel Reference Survey Galaxies
Authors: Ciesla Laure ,   the SAG2 Consortium
Published: March 2013

The Herschel Reference Survey is a guaranteed time key project aimed at studying the physical properties of the interstellar medium (ISM) of 323 nearby galaxies, covered by multi-wavelength data. This volume limited, K-band selected sample is composed of galaxies spanning the whole range of morphological types and environments. We conduct a statistical study on the ISM properties of nearby galaxies based on the analysis of their SED. To achieve this goal, we fit the data with the models of Draine & Li (2007) to obtain the intensity of interstellar radiation field, the PAH abundance, the contribution of photodissociation regions, and the dust mass.