First detection of the field star overdensity in the Perseus arm

Monguió, M.; Grosbøl, P.; Figueras, F.

doi:10.1051/0004-6361/201424896

Cited by 27 publications

(24 citation statements)

References 41 publications

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“…Elias et al (2009) found that spatial distribution and kinematics of stars in Ori OB1 and Sco OB2 (distance from the Sun is 0.1-0.6 kpc (Mel'Nik & Dambis 2009)) would be explained if they were located close to the corotation zone. Antoja et al (2011) and Monguió et al (2015) studied stellar kinematics in the solar neighborhood and located the co-rotation radius at about 2 kpc beyond the solar circle. Griv et al Griv et al (2015) obtained the position of the co-rotation radius about 9.9 kpc.…”

Section: Discussionmentioning

confidence: 99%

Gas kinematics in high-mass star-forming regions from the Perseus spiral arm

2017

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We present results of a survey of 14 star-forming regions from the Perseus spiral arm in CS (2-1) and 13 CO (1-0) lines with the Onsala Space Observatory 20 m telescope. Maps of 10 sources in both lines were obtained. For the remaining sources a map in just one line or a single-point spectrum were obtained. On the basis of newly obtained and published observational data we consider the relation between velocities of the "quasi-thermal" CS (2-1) line and 6.7 GHz methanol maser line in 24 high-mass star-forming regions in the Perseus arm. We show that, surprisingly, velocity ranges of 6.7 GHz methanol maser emission are predominantly red-shifted with respect to corresponding CS (2-1) line velocity ranges in the Perseus arm. We suggest that the predominance of the "red-shifted masers" in the Perseus arm could be related to the alignment of gas flows caused by the large-scale motions in the Galaxy. Large-scale galactic shock related to the spiral structure is supposed to affect the local kinematics of the star-forming regions. Part of the Perseus arm, between galactic longitudes from 85 • to 124 • , does not contain blue-shifted masers at all. Radial velocities of the sources are the greatest in this particular part of the arm, so the velocity difference is clearly pronounced. 13 CO (1-0) and CS (2-1) velocity maps of G183.35-0.58 show gas velocity difference between the center and the periphery of the molecular clump up to 1.2 km s −1 . Similar situation is likely to occur in G85.40-0.00. This can correspond to the case when the large-scale shock wave entrains the outer parts of a molecular clump in motion while the dense central clump is less affected by the shock.

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Section: Discussionmentioning

confidence: 99%

Gas kinematics in high-mass star-forming regions from the Perseus spiral arm

2017

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“…Mishurov & Zenina (1999) and Dias & Lépine (2005) located it very close to the Solar orbit radius. However, Drimmel & Spergel (2001) located it at 6.7 kpc, Acharova et al (2012) at 7 kpc, and Monguió et al (2015) places it farther away than the Perseus arm. Recently, Michtchenko et al (2018) explained the moving groups observed in the solar neighborhood based on a model which places Rc close to the Sun.…”

Section: Introductionmentioning

confidence: 92%

The spiral pattern rotation speed of the Galaxy and the corotation radius with Gaia DR2

Dias

Monteiro

Lépine

et al. 2019

Monthly Notices of the Royal Astronomical Society

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In this work we revisit the issue of the rotation speed of the spiral arms and the location of the corotation radius of our Galaxy. This research was performed using homogeneous data set of young open clusters (age < 50 Myr) determined from Gaia DR2 data. The stellar astrometric membership were determined using proper motions and parallaxes, taking into account the full covariance matrix. The distance, age, reddening and metallicity of the clusters were determined by our non subjective multidimensional global optimization tool to fit theoretical isochrones to Gaia DR2 photometric data. The rotation speed of the arms is obtained from the relation between age and angular distance of the birthplace of the clusters to the present-day position of the arms. Using the clusters belonging to the Sagittarius-Carina, Local and Perseus arms, and adopting the Galactic parameters R 0 = 8.3 kpc and V 0 = 240 km s −1 , we determine a pattern speed of 28.2 ± 2.1 km s −1 kpc −1 , with no difference between the arms. This implies that the corotation radius is R c = 8.51 ± 0.64 kpc, close to the solar Galactic orbit (R c /R 0 = 1.02 ± 0.07).

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“…To assess whether our data can expose such an effect, we examine the = 178 • sight line, since it is close to the radial direction that minimises shear due to Galactic rotation and more easily reveals low-amplitude perturbations that may be associated with spiral arm structure. Monguió, Grosbøl & Figueras (2015) used B4-A1 stars to find a stellar overdensity due to the Perseus spiral arm at a heliocentric distance of 1.6 ± 0.2 kpc in the anticentre direction, and Reid et al (2014) used parallaxes of 24 star forming regions to find the arm to be located at 2 kpc. The Perseus Arm is therefore located just short of the sampled region in this work.…”

Section: Spiral Arm Perturbationsmentioning

confidence: 99%

A and F stars as probes of outer Galactic disc kinematics

Harris

Drew

Farnhill

et al. 2018

Monthly Notices of the Royal Astronomical Society

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Previous studies of the rotation law in the outer Galactic disc have mainly used gas tracers or clump giants. Here, we explore A and F stars as alternatives: these provide a much denser sampling in the outer disc than gas tracers and have experienced significantly less velocity scattering than older clump giants. This first investigation confirms the suitability of A stars in this role. Our work is based on spectroscopy of ∼ 1300 photometrically-selected stars in the red calcium-triplet region, chosen to mitigate against the effects of interstellar extinction. The stars are located in two low Galactic latitude sightlines, at longitudes = 118• , sampling strong Galactic rotation shear, and = 178• , near the Anticentre. With the use of Markov Chain Monte Carlo parameter fitting, stellar parameters and radial velocities are measured, and distances computed. The obtained trend of radial velocity with distance is inconsistent with existing flat or slowly rising rotation laws from gas tracers (Brand & Blitz 1993;Reid et al. 2014). Instead, our results fit in with those obtained by Huang et al. (2016) from disc clump giants that favoured rising circular speeds. An alternative interpretation in terms of spiral arm perturbation is not straight forward. We assess the role that undetected binaries in the sample and distance error may have in introducing bias, and show that the former is a minor factor. The random errors in our trend of circular velocity are within ±5 km s −1 .

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First detection of the field star overdensity in the Perseus arm

Cited by 27 publications

References 41 publications

Gas kinematics in high-mass star-forming regions from the Perseus spiral arm

Gas kinematics in high-mass star-forming regions from the Perseus spiral arm

The spiral pattern rotation speed of the Galaxy and the corotation radius with Gaia DR2

A and F stars as probes of outer Galactic disc kinematics

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