A global view on star formation: The GLOSTAR Galactic plane survey. II. Supernova remnants in the first quadrant of the Milky Way

This review examines the state-of-the-art knowledge of high-mass star and massive cluster formation, gained from ambitious observational surveys, which acknowledges the multiscale characteristics of these processes. After a brief overview of theoretical models and main open issues, we present observational searches for the evolutionary phases of high-mass star formation, first among high-luminosity sources and more recently among young massive protostars and the elusive high-mass prestellar cores. We then introduce the most likely evolutionary scenario for high-mass star formation, which emphasizes the link of high-mass star formation to massive cloud and cluster formation. Finally, we introduce the first attempts to search for variations of the star-formation activity and cluster formation in molecular cloud complexes in the most extreme star-forming sites and across the Milky Way. The combination of Galactic plane surveys and high–angular resolution images with submillimeter facilities such as Atacama Large Millimeter Array (ALMA) are prerequisites to make significant progress in the forthcoming decade.

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A Global View on Star Formation: The GLOSTAR Galactic Plane Survey. III. 6.7 GHz Methanol maser survey in Cygnus X

Astronomy and Astrophysics ◽

10.1051/0004-6361/202140817 ◽

2021 ◽

Author(s):

G. Ortiz-Leon ◽

K. M. Menten ◽

A. Brunthaler ◽

T. Csengeri ◽

J. S. Urquhart ◽

...

Keyword(s):

Star Formation ◽

Galactic Plane ◽

Methanol Maser ◽

Global View

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Radio continuum emission in the northern Galactic plane: Sources and spectral indices from the THOR survey

Astronomy and Astrophysics ◽

10.1051/0004-6361/201833642 ◽

2018 ◽

Vol 619 ◽

pp. A124 ◽

Cited By ~ 16

Author(s):

Y. Wang ◽

S. Bihr ◽

M. Rugel ◽

H. Beuther ◽

K. G. Johnston ◽

...

Keyword(s):

Supernova Remnants ◽

Milky Way ◽

Galactic Plane ◽

High Redshift ◽

High Sensitivity ◽

Large Percentage ◽

Radio Continuum ◽

Continuum Emission ◽

High Angular Resolution ◽

Spectral Indices

Context Radio continuum surveys of the Galactic plane can find and characterize H II regions, supernova remnants (SNRs), planetary nebulae (PNe), and extragalactic sources. A number of surveys at high angular resolution (≤25″) at different wavelengths exist to study the interstellar medium (ISM), but no comparable high-resolution and high-sensitivity survey exists at long radio wavelengths around 21 cm. Aims. Our goal is to investigate the 21 cm radio continuum emission in the northern Galactic plane at < 25″ resolution. Methods We observed a large percentage of the Galactic plane in the first quadrant of the Milky Way (l = 14.0−67.4° and |b| ≤ 1.25°) with the Karl G. Jansky Very Large Array (VLA) in the C-configuration covering six continuum spectral windows (SPW). These data provide a detailed view on the compact as well as extended radio emission of our Galaxy and thousands of extragalactic background sources. Results We used the BLOBCAT software and extracted 10 916 sources. After removing spurious source detections caused by the side lobes of the synthesized beam, we classified 10 387 sources as reliable detections. We smoothed the images to a common resolution of 25″ and extracted the peak flux density of each source in each SPW to determine the spectral indices α (assuming I(ν) ∝ να). By cross-matching with catalogs of H II regions, SNRs, PNe, and pulsars, we found radio counterparts for 840 H II regions, 52 SNRs, 164 PNe, and 38 pulsars. We found 79 continuum sources that are associated with X-ray sources. We identified 699 ultra-steep spectral sources (α < −1.3) that could be high-redshift galaxies. About 9000 of the sources we extracted are not classified specifically, but based on their spatial and spectral distribution, a large percentage of these are likely to be extragalactic background sources. More than 7750 sources do not have counterparts in the SIMBAD database and more than 3760 sources do not have counterparts in the NED database. Conclusions Studying the long wavelengths centimeter continuum emission and the associated spectral indices allows us to characaterize a large percentage of Galactic and extragalactic radio sources in the area of the northern inner Milky Way. This database will be extremely useful for future studies of a diverse set of astrophysical objects.

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Integrated data access, visualization and analysis for Galactic Plane surveys: the VIALACTEA case

Proceedings of the International Astronomical Union ◽

10.1017/s1743921317000163 ◽

2016 ◽

Vol 12 (S325) ◽

pp. 291-298 ◽

Cited By ~ 1

Author(s):

Sergio Molinari ◽

Robert Butora ◽

Stefano Cavuoti ◽

Marco Molinaro ◽

Giuseppe Riccio ◽

...

Keyword(s):

Star Formation ◽

Visual Analytics ◽

Milky Way ◽

Galactic Plane ◽

Data Access ◽

Automated Analysis ◽

Spectral Energy ◽

Data Mining Algorithms ◽

Molecular Lines ◽

Stored Information

AbstractThe VIALACTEA project brings to a common forum the major new-generation surveys of the Milky Way Galactic Plane from 1μm to the radio, both in thermal continuum and in atomic and molecular lines, to attack in a systematic way the characterization of the Milky Way as a star formation engine. Images, catalogues, spectroscopic datacubes and radiative transfer models of the Spectral Energy Distributions (SEDs) of sites of star formation have been incorporated and indexed in the VIALACTEA Knowledge Base (VLKB). The VLKB consists of a combination of a relational database where the VIALACTEA data and metadata are homogenised and stored, and a filesystem-based stored information. This infrastructure allowed, among others, the generation of extensive catalogue for compact sources and extended structures in the Galactic Plane, the implementation of data-mining algorithms for the band-merging of multiwavelength data and expert systems for the automated analysis of molecular line surveys to extract critical kinematical information and derive distances using Galaxy rotation curves and new 3D extinction maps. A new VIALACTEA 3D Visual Analytics interface has been developed that provides integrated access and analysis of continuum and spectroscopic images together with catalogue data directly interfacing with the VLKB.

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VINTERGATAN III: how to reset the metallicity of the Milky Way

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stab543 ◽

2021 ◽

Vol 503 (4) ◽

pp. 5868-5876

Author(s):

Florent Renaud ◽

Oscar Agertz ◽

Eric P Andersson ◽

Justin I Read ◽

Nils Ryde ◽

...

Keyword(s):

Star Formation ◽

Milky Way ◽

Galactic Plane ◽

First Stars ◽

Massive Galaxies ◽

The Galaxy ◽

Chemical Content ◽

Major Merger ◽

Purely Sequential

ABSTRACT Using the cosmological zoom simulation VINTERGATAN, we present a new scenario for the onset of star formation at the metal-poor end of the low-[α/Fe] sequence in a Milky Way-like galaxy. In this scenario, the galaxy is fuelled by two distinct gas flows. One is enriched by outflows from massive galaxies, but not the other. While the former feeds the inner galactic region, the latter fuels an outer gas disc, inclined with respect to the main galactic plane, and with a significantly poorer chemical content. The first passage of the last major merger galaxy triggers tidal compression in the outer disc, which increases the gas density and eventually leads to star formation, at a metallicity 0.75 dex lower than the inner galaxy. This forms the first stars of the low-[α/Fe] sequence. These in situ stars have halo-like kinematics, similar to what is observed in the Milky Way, due to the inclination of the outer disc that eventually aligns with the inner one via gravitational torques. We show that this tilting disc scenario is likely to be common in Milky Way-like galaxies. This process implies that the low-[α/Fe] sequence is populated in situ, simultaneously from two formation channels, in the inner and the outer galaxy, with distinct metallicities. This contrasts with purely sequential scenarios for the assembly of the Milky Way disc and could be tested observationally.

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Methanol masers in the Herschel era Putting them in the star formation context

Proceedings of the International Astronomical Union ◽

10.1017/s1743921312007582 ◽

2012 ◽

Vol 8 (S287) ◽

pp. 492-496

Author(s):

Michele Pestalozzi

Keyword(s):

Star Formation ◽

Milky Way ◽

Galactic Plane ◽

High Mass ◽

Space Observatory ◽

Methanol Maser ◽

Open Time ◽

The Galaxy ◽

Methanol Masers ◽

Using Data

AbstractMethanol masers are known to be among the most reliable tracers of high-mass stars in early stages of evolution. A number of searches across the Galaxy has yielded to date, a complete census of those masers in two thirds of the Milky Way, providing a catalogue of some 800 sources to be studied in depth. In particular, it is important to characterise the physical properties of the objects hosting methanol masers, and this is possible today using data from the Herschel Space Observatory (HSO). The exceptional spatial resolution of HSO and its wavelength coverage are perfectly tuned to put the methanol maser phase into its star formation context. This paper presents results on the characterisation of methanol maser hosts using Herschel data from the Hi-GAL project, an Open Time Key Project to survey the inner Galactic plane at 5 wavelengths between 70 and 500 μm.

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The Ratan Galactic Plane Survey

Symposium - International Astronomical Union ◽

10.1017/s007418090012830x ◽

1998 ◽

Vol 179 ◽

pp. 103-105

Author(s):

S.A. Trushkin

Keyword(s):

Spectral Data ◽

Supernova Remnants ◽

Milky Way ◽

Galactic Plane ◽

Radio Continuum ◽

Radio Sources ◽

Optical Identification ◽

Source Distance ◽

The Galaxy

Now in radio continuum surveys more than 10,000 radio sources have discovered in the Milky Way plane but the Galactic origin only of a small part of them has been determined. The problem comes from the absence of estimates of source distance and the optical identification even for bright radio sources, and the most of sources have not spectral data at 2-3 frequencies. As followed some hundreds of sources have not classified as thermal or non-thermal. Now we don't know the full number of supernova remnants (SNRs) in the Galaxy. The simple estimates show that a sample of Galactic SNRs is not full as for weak and extended (> 15′) as for bright and compact (< 3′) SNRs (Trushkin 1993).

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