scholarly journals Detection of new O-type stars in the obscured stellar cluster Tr 16-SE in the Carina Nebula with KMOS

2021 ◽  
Vol 648 ◽  
pp. A34
Author(s):  
T. Preibisch ◽  
S. Flaischlen ◽  
C. Göppl ◽  
B. Ercolano ◽  
V. Roccatagliata
Keyword(s):  
Large Population ◽  
High Mass ◽  
Infrared Spectroscopic Study ◽  
Be Stars ◽  
Stellar Cluster ◽  
Dark Clouds ◽  
Carina Nebula ◽  
Integral Field Spectrograph ◽  
Band Spectra ◽  
Integral Field

Context. The Carina Nebula harbors a large population of high-mass stars, including at least 75 O-type and Wolf-Rayet (WR) stars, but the current census is not complete since further high-mass stars may be hidden in or behind the dense dark clouds that pervade the association. Aims. With the aim of identifying optically obscured O- and early B-type stars in the Carina Nebula, we performed the first infrared spectroscopic study of stars in the optically obscured stellar cluster Tr 16-SE, located behind a dark dust lane south of η Car. Methods. We used the integral-field spectrograph KMOS at the ESO VLT to obtain H- and K-band spectra with a resolution of R ≈ 4000 (Δλ ≈ 5 Å) for 45 out of the 47 possible OB candidate stars in Tr 16-SE, and we derived spectral types for these stars. Results. We find 15 stars in Tr 16-SE with spectral types between O5 and B2 (i.e., high-mass stars with M ≥ 8 M⊙), only two of which were known before. An additional nine stars are classified as (Ae)Be stars (i.e., intermediate-mass pre-main-sequence stars), and most of the remaining targets show clear signatures of being late-type stars and are thus most likely foreground stars or background giants unrelated to the Carina Nebula. Our estimates of the stellar luminosities suggest that nine of the 15 O- and early B-type stars are members of Tr 16-SE, whereas the other six seem to be background objects. Conclusions. Our study increases the number of spectroscopically identified high-mass stars (M ≥ 8 M⊙) in Tr 16-SE from two to nine and shows that Tr 16-SE is one of the larger clusters in the Carina Nebula. Our identification of three new stars with spectral types between O5 and O7 and four new stars with spectral types O9 to B1 significantly increases the number of spectroscopically identified O-type stars in the Carina Nebula.

scholarly journals Observational Studies of Pre-Stellar Cores and Infrared Dark Clouds

2011 ◽  
Vol 7 (S280) ◽  
pp. 19-32 ◽  
Author(s):  
Paola Caselli
Keyword(s):  
Molecular Cloud ◽  
Chemical Structure ◽  
Initial Conditions ◽  
Theoretical Work ◽  
High Mass ◽  
Mass Star ◽  
Stellar Cluster ◽  
Dark Clouds ◽  
Low Mass ◽  
Infrared Dark Clouds

AbstractStars like our Sun and planets like our Earth form in dense regions within interstellar molecular clouds, called pre-stellar cores (PSCs). PSCs provide the initial conditions in the process of star and planet formation. In the past 15 years, detailed observations of (low-mass) PSCs in nearby molecular cloud complexes have allowed us to find that they are cold (T < 10K) and quiescent (molecular line widths are close to thermal), with a chemistry profoundly affected by molecular freeze-out onto dust grains. In these conditions, deuterated molecules flourish, becoming the best tools to unveil the PSC physical and chemical structure. Despite their apparent simplicity, PSCs still offer puzzles to solve and they are far from being completely understood. For example, what is happening to the gas and dust in their nuclei (the future stellar cradles) is still a mystery that awaits for ALMA. Other important questions are: how do different environments and external conditions affect the PSC physical/chemical structure? Are PSCs in high-mass star forming regions similar to the well-known low-mass PSCs? Here I review observational and theoretical work on PSCs in nearby molecular cloud complexes and the ongoing search and study of massive PSCs embedded in infrared dark clouds (IRDCs), which host the initial conditions for stellar cluster and high-mass star formation.

scholarly journals Nitrogen and hydrogen fractionation in high-mass star-forming cores from observations of HCN and HNC

2018 ◽  
Vol 609 ◽  
pp. A129 ◽  
Author(s):  
L. Colzi ◽  
F. Fontani ◽  
P. Caselli ◽  
C. Ceccarelli ◽  
P. Hily-Blant ◽  
...  
Keyword(s):  
Solar System ◽  
Solar Nebula ◽  
Rotational Transition ◽  
High Mass ◽  
Evolutionary Stage ◽  
Mass Star ◽  
Stellar Cluster ◽  
Star Forming ◽  
Star Forming Regions ◽  
Dense Cores

The ratio between the two stable isotopes of nitrogen, 14N and 15N, is well measured in the terrestrial atmosphere (~272), and for the pre-solar nebula (~441, deduced from the solar wind). Interestingly, some pristine solar system materials show enrichments in 15N with respect to the pre-solar nebula value. However, it is not yet clear if and how these enrichments are linked to the past chemical history because we have only a limited number of measurements in dense star-forming regions. In this respect, dense cores, which are believed to be the precursors of clusters and also contain intermediate- and high-mass stars, are important targets because the solar system was probably born within a rich stellar cluster, and such clusters are formed in high-mass star-forming regions. The number of observations in such high-mass dense cores has remained limited so far. In this work, we show the results of IRAM-30 m observations of the J = 1−0 rotational transition of the molecules HCN and HNC and their 15N-bearing counterparts towards 27 intermediate- and high-mass dense cores that are divided almost equally into three evolutionary categories: high-mass starless cores, high-mass protostellar objects, and ultra-compact Hii regions. We have also observed the DNC(2–1) rotational transition in order to search for a relation between the isotopic ratios D/H and 14N/15N. We derive average 14N/15N ratios of 359 ± 16 in HCN and of 438 ± 21 in HNC, with a dispersion of about 150–200. We find no trend of the 14N/15N ratio with evolutionary stage. This result agrees with what has been found for N2H+ and its isotopologues in the same sources, although the 14N/15N ratios from N2H+ show a higher dispersion than in HCN/HNC, and on average, their uncertainties are larger as well. Moreover, we have found no correlation between D/H and 14N/15N in HNC. These findings indicate that (1) the chemical evolution does not seem to play a role in the fractionation of nitrogen, and that (2) the fractionation of hydrogen and nitrogen in these objects is not related.

The first VisAO-fed integral field spectrograph: VisAO IFS

2010 ◽  
Author(s):  
Katherine B. Follette ◽  
Laird M. Close ◽  
Derek Kopon ◽  
Jared R. Males ◽  
Victor Gasho ◽  
...  
Keyword(s):  
Integral Field Spectrograph ◽  
Integral Field

HARMONI: A Narrow Field Near-infrared Integral Field Spectrograph for the E-ELT

2009 ◽  
pp. 267-271 ◽  
Author(s):  
Matthias Tecza ◽  
Niranjan Thatte ◽  
Fraser Clarke ◽  
David Freeman
Keyword(s):  
Near Infrared ◽  
Integral Field Spectrograph ◽  
Integral Field

scholarly journals The MURALES survey

2020 ◽  
Vol 645 ◽  
pp. A12
Author(s):  
B. Balmaverde ◽  
A. Capetti ◽  
A. Marconi ◽  
G. Venturi ◽  
M. Chiaberge ◽  
...  
Keyword(s):  
Emission Line ◽  
Large Scale ◽  
Line Emission ◽  
Emission Region ◽  
Gas Velocity ◽  
Ionized Gas ◽  
Large Scale Structures ◽  
Scale Structures ◽  
Integral Field Spectrograph ◽  
Integral Field

We present the final observations of a complete sample of 37 radio galaxies from the Third Cambridge Catalogue (3C) with redshift < 0.3 and declination < 20° obtained with the VLT/MUSE optical integral field spectrograph. These data were obtained as part of the MUse RAdio Loud Emission line Snapshot (MURALES) survey with the main goal of exploring the AGN feedback process in the most powerful radio sources. We present the data analysis and, for each source, the resulting emission line images and the 2D gas velocity field. Thanks to the unprecedented depth these observations reveal emission line regions (ELRs) extending several tens of kiloparsec in most objects. The gas velocity shows ordered rotation in 25 galaxies, but in several sources it is highly complex. We find that the 3C sources show a connection between radio morphology and emission line properties. In the ten FR I sources the line emission region is generally compact, only a few kpc in size; only in one case does it exceed the size of the host. Conversely, all but two of the FR II galaxies show large-scale structures of ionized gas. The median extent is 16 kpc with the maximum reaching a size of ∼80 kpc. There are no apparent differences in extent or strength between the ELR properties of the FR II sources of high and low gas excitation. We confirm that the previous optical identification of 3C 258 is incorrect: this radio source is likely associated with a quasi-stellar object at z ∼ 1.54.

scholarly journals The MAGNUM survey: a high-resolution study of the complex nuclear environment of local Seyfert galaxies

2019 ◽  
pp. 159-172
Author(s):  
M. Mingozzi ◽  
G. Venturi ◽  
F. Mannucci ◽  
A. Marconi ◽  
G. Cresci
Keyword(s):  
Seyfert Galaxies ◽  
Analysis Techniques ◽  
Central Regions ◽  
Galaxy Disk ◽  
Nuclear Environment ◽  
Physical Effects ◽  
Integral Field Spectrograph ◽  
Inner Parts ◽  
Integral Field ◽  
Extract Information

The central regions of Seyfert galaxies, comprising broad and narrow line regions and the inner parts of galaxy disk and bulge, is characterized by a complex interplay among many physical effects. Specifically, it is shaped by the influence of the central black hole, producing ionization by an hard continuum and gas outflows. The integral-field spectrograph MUSE at the ESO VLT allows to carry out a detailed study of these regions to obtain their ionization, dynamical, and metallicity properties. Here we present some highlights of the MAGNUM survey which is designed to study the central regions of a sample of nearby (D > 500 pc) Seyfert galaxies. We describe the rationale of the survey, the data analysis techniques used to extract information on ionization and dynamics, and the results for one galaxy, Centaurus A.

scholarly journals DARKNESS: A Microwave Kinetic Inductance Detector Integral Field Spectrograph for High-contrast Astronomy

2018 ◽  
Vol 130 (988) ◽  
pp. 065001 ◽  
Author(s):  
Seth R. Meeker ◽  
Benjamin A. Mazin ◽  
Alex B. Walter ◽  
Paschal Strader ◽  
Neelay Fruitwala ◽  
...  
Keyword(s):  
Kinetic Inductance Detector ◽  
Kinetic Inductance ◽  
High Contrast ◽  
Microwave Kinetic Inductance Detector ◽  
Integral Field Spectrograph ◽  
Integral Field

The Visible Integral-field Spectrograph eXtreme (VIS-X): a high-resolution spectrograph for MagAO-X

2021 ◽  
Author(s):  
Sebastiaan Y. Haffert ◽  
Jared Males ◽  
Laird Close ◽  
Joseph Long ◽  
Lauren Schatz ◽  
...  
Keyword(s):  
High Resolution ◽  
Integral Field Spectrograph ◽  
Integral Field

scholarly journals Stellar dynamics of galactic nuclei with TIGER

1995 ◽  
Vol 149 ◽  
pp. 282-287 ◽  
Author(s):  
Eric Emsellem ◽  
Roland Bacon ◽  
Guy Monnet
Keyword(s):  
Black Holes ◽  
Galactic Nuclei ◽  
Stellar Dynamics ◽  
Dynamical Structure ◽  
M 31 ◽  
Dynamical Properties ◽  
Integral Field Spectrograph ◽  
Integral Field ◽  
Observational Program

AbstractWe conducted an observational program using the TIGER integral field spectrograph to study the dynamical structure of nearby galactic nuclei. We already obtained new original results on three of the best ”Black Holes Candidates”: M 32, M 31 and M 104. Their nuclei exhibit complex morphologies and unusual dynamical properties such as: asymmetries, anisotropy, triaxiality which would have been impossible to detect with a ”classical“ spectrograph.

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