45 research outputs found
12CO and 13CO J=3-2 observations toward N11 in the Large Magellanic Cloud
After 30 Doradus, N11 is the second largest and brightest nebula in the LMC.
This large nebula has several OB associations with bright nebulae at its
surroundings. N11 was previously mapped at the lowest rotational transitions of
CO (J=1--0 and 2--1), and in some particular regions pointings of the
CO J=1--0 and 2--1 lines were also performed. Using ASTE we mapped the
whole extension of the N11 nebula in the CO J=3--2 line, and three
sub-regions in the CO J=3--2 line. The regions mapped in the CO
J=3--2 were selected based on that they may be exposed to the radiation at
different ways: a region lying over the nebula related to the OB association
LH10 (N11B), another one that it is associated with the southern part of the
nebula related to the OB association LH13 (N11D), and finally a farther area at
the southwest without any embedded OB association (N11I). We found that the
morphology of the molecular clouds lying in each region shows some signatures
that could be explained by the expansion of the nebulae and the action of the
radiation. Fragmentation generated in a molecular shell due to the expansion of
the N11 nebula is suggested. The integrated line ratios CO/CO
show evidences of selective photodissociation of the CO, and probably
other mechanisms such as chemical fractionation. The CO contribution to the
continuum at 870 m was directly derived. The distribution of the
integrated line ratios CO J=3--2/2--1 show hints of stellar feedback in
N11B and N11D. The ratio between the virial and LTE mass (M/M) is higher than unity in all analyzed molecular clumps, which suggests
that the clumps are not gravitationally bounded and may be supported by
external pressure. A non-LTE analysis suggests that we are mapping gas with
densities about a few 10 cm.Comment: Accepted to be published in A&A. Figures were degrade
The molecular environment of the pillar-like features in the HII region G46.5-0.2
At the interface of HII regions and molecular gas peculiar structures appear,
some of them with pillar-like shapes. Understanding their origin is important
for characterizing triggered star formation and the impact of massive stars on
the interstellar medium. In order to study the molecular environment and the
influence of the radiation on two pillar-like features related to the HII
region G46.5-0.2, we performed molecular line observations with the Atacama
Submillimeter Telescope Experiment, and spectroscopic optical observations with
the Isaac Newton Telescope. From the optical observations we identified the
star that is exciting the HII region as a spectral type O4-6. The molecular
data allowed us to study the structure of the pillars and a HCO+ cloud lying
between them. In this HCO+ cloud, which have not any well defined 12CO
counterpart, we found direct evidence of star formation: two molecular outflows
and two associated near-IR nebulosities. The outflows axis orientation is
perpendicular to the direction of the radiation flow from the HII region.
Several Class I sources are also embedded in this HCO+ cloud, showing that it
is usual that the YSOs form large associations occupying a cavity bounded by
pillars. On the other hand, it was confirmed that the RDI process is not
occurring in one of the pillar tips.Comment: Accepted in MNRAS (2017 June 13
Studying star-forming processes at core and clump scales: the case of the young stellar object G29.862-0.0044
Massive molecular clumps fragment into cores where star formation takes
place, hence star-forming studies should be done at different spatial scales.
Using near-IR data obtained with Gemini, data of CH3OCHO and CH3CN from the
ALMA database, observations of HCN, HNC, HCO+, and C2H carried out with ASTE,
and CO data from public surveys, we perform a deep study of the YSO
G29.86-0.004 at core and clump spatial scales. The near-IR emission shows two
nebulosities separated by a dark lane, suggesting a typical disk-jets system,
but highly asymmetric. They are likely produced by scattered light in cavities
carved out by jets on an infalling envelope of material, which also present
line emission of H2 and [FeII]. The presence of the complex molecular species
observed with ALMA confirms that we are mapping a hot molecular core. The CH3CN
emission concentrates at the position of the dark lane and it appears slightly
elongated from southwest to northeast in agreement with the inclination of the
system as observed at near-IR. The morphology of the CH3OCHO emission is more
complex and extends along some filaments and concentrates in knots and clumps,
mainly southwards the dark-lane, suggesting that the southern jet is
encountering a dense region. The northern jet flows more freely, generating
more extended features. This is in agreement with the red-shifted molecular
outflow traced by the 12CO J=3-2 line extending towards the northwest and the
lack of a blue-shifted outflow. This configuration can be explained by
considering that the YSO is located at the furthest edge of the molecular clump
along the line of sight, which is consistent with the position of the source in
the cloud mapped in the C18O J=3-2 line. The detection of HCN, HNC, HCO+, and
C2H allowed us to characterize the dense gas at clump scales, yielding results
that are in agreement with the presence of a high-mass protostellar object.Comment: Accepted to be published in A&A (July 13, 2020
The southern molecular environment of SNR G18.8+0.3
In a previous paper we have investigated the molecular environment towardsthe eastern border of the SNR G18.8+0.3. Continuing with the study of thesurroundings of this SNR, in this work we focus on its southern border, whichin the radio continuum emission shows a very peculiar morphology with acorrugated corner and a very flattened southern flank. We observed two regionstowards the south of SNR G18.8+0.3 using the Atacama Submillimeter TelescopeExperiment (ASTE) in the 12CO J=3-2. One of these regions was also surveyed in13CO and C18O J=3-2. The angular and spectral resolution of these observationswere 22", and 0.11 km/s. We compared the CO emission to 20 cm radio continuummaps obtain as part of the Multi-Array Galactic Plane Imaging Survey (MAGPIS)and 870 um dust emission extracted from the APEX Telescope Large Area Survey ofthe Galaxy. We discovered a molecular feature with a good morphologicalcorrespondence with the SNR´s southernmost corner. In particular, there areindentations in the radio continuum map that are complemented by protrusions inthe molecular CO image, strongly suggesting that the SNR shock is interactingwith a molecular cloud. Towards this region we found that the 12CO peak is notcorrelated with the observed 13CO peaks, which are likely related to a nearby Hii region. Regarding the most flattened border of SNR G18.8+0.3, where aninteraction of the SNR with dense material was previously suggested, our 12COJ=3-2 map show no obvious indication that this is occurring.Fil: Paron, Sergio Ariel. Consejo Nacional de Investigaciónes CientÃficas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de AstronomÃa y FÃsica del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de AstronomÃa y FÃsica del Espacio; ArgentinaFil: Celis Peña, Mariela Fernanda. Consejo Nacional de Investigaciónes CientÃficas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de AstronomÃa y FÃsica del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de AstronomÃa y FÃsica del Espacio; ArgentinaFil: Ortega, Martin Eduardo. Consejo Nacional de Investigaciónes CientÃficas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de AstronomÃa y FÃsica del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de AstronomÃa y FÃsica del Espacio; ArgentinaFil: Petriella, Alberto. Consejo Nacional de Investigaciónes CientÃficas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de AstronomÃa y FÃsica del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de AstronomÃa y FÃsica del Espacio; ArgentinaFil: Rubio, M.. Universidad de Chile. Facultad de Ciencias Fisicas y Matematicas; ChileFil: Dubner, Gloria Mabel. Consejo Nacional de Investigaciónes CientÃficas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de AstronomÃa y FÃsica del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de AstronomÃa y FÃsica del Espacio; ArgentinaFil: Giacani, Elsa Beatriz. Consejo Nacional de Investigaciónes CientÃficas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de AstronomÃa y FÃsica del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de AstronomÃa y FÃsica del Espacio; Argentin
The molecular environment of the pillar-like features in the H ii region G46.5–0.2
At the interface of HII regions and molecular gas, peculiar structuresappear, some of them with pillar-like shapes. Understanding their originis important for characterizing triggered star formation and the impactof massive stars on the interstellar medium. In order to study themolecular environment and influence of radiation on two pillar-likefeatures related to the H ii region G46.5-0.2, we performed molecularline observations with the Atacama Submillimeter Telescope Experimentand spectroscopic optical observations with the Isaac Newton Telescope.From the optical observations, we identified the star that is excitingthe H ii region as spectral type O4-6. The molecular data allowed us tostudy the structure of the pillars and an HCO+ cloud lyingbetween them. In this HCO+ cloud, which has no well-defined12CO counterpart, we found direct evidence of star formation:two molecular outflows and two associated near-IR nebulosities. Theoutflow axis orientation is perpendicular to the direction of theradiation flow from the HII region. Several Class I sources are alsoembedded in this HCO+ cloud, showing that it is usual thatyoung stellar objects (YSOs) form large associations occupying a cavitybounded by pillars. On the other hand, it was confirmed that theradiation-driven implosion (RDI) process is not occurring in one of thepillar tips.Fil: Paron, Sergio Ariel. Consejo Nacional de Investigaciónes CientÃficas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de AstronomÃa y FÃsica del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de AstronomÃa y FÃsica del Espacio; ArgentinaFil: Celis Peña, Mariela Fernanda. Consejo Nacional de Investigaciónes CientÃficas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de AstronomÃa y FÃsica del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de AstronomÃa y FÃsica del Espacio; ArgentinaFil: Ortega, Martin Eduardo. Consejo Nacional de Investigaciónes CientÃficas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de AstronomÃa y FÃsica del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de AstronomÃa y FÃsica del Espacio; ArgentinaFil: Fariña, Cecilia Silvia. Isaac Newton Group Of Telescopes, Las Palmas, Iac; EspañaFil: Petriella, Alberto. Consejo Nacional de Investigaciónes CientÃficas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de AstronomÃa y FÃsica del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de AstronomÃa y FÃsica del Espacio; ArgentinaFil: Rubio, M.. Departamento de AstronomÃa, Universidad de Chile; ChileFil: Ashley, R. P.. University Of Warwick; Reino Unid
Ulcerative colitis seems to imply oral microbiome dysbiosis
Ulcerative colitis (UC) is a recurrent pathology of complex etiology that has been occasionally associated with oral lesions, but the overall composition of the oral microbiome in UC patients and its role in the pathogenesis of the disease are still poorly understood. In this study, the oral microbiome of UC patients and healthy individuals was compared to ascertain the possible changes in the oral microbial communities associated with UC. For this, the salivary microbiota of 10 patients diagnosed with an active phase of UC and 11 healthy controls was analyzed by 16S rRNA gene sequencing (trial ref. ISRCTN39987). Metataxonomic analysis revealed a decrease in the alpha diversity and an imbalance in the relative proportions of some key members of the oral core microbiome in UC patients. Additionally, Staphylococcus members and four differential species or phylotypes were only present in UC patients, not being detected in healthy subjects. This study provides a global snapshot of the existence of oral dysbiosis associated with UC, and the possible presence of potential oral biomarkers