BVR photometric investigation of galaxy pair KPG 562

Context. The outer Galactic disc contains some features such as the warp and flare, whose origin is still debated. The Gaia data provide an excellent opportunity to probe the Galactic disc at large distances and study these features. Aims. We derive the density distributions of the average (old) whole population and the supergiants (representative of a young population), and we use them to constrain their warp and flare. By comparing the results, we study how the properties of these phenomena depend on the studied population. Methods. We used Lucy's deconvolution method to recover corrected star counts as a function of distance, from which we derive the density distribution. Results. We find that supergiants have an asymmetric warp, reaching a maximum amplitude of z w = 0.658 kpc and minimum amplitude of z w = −0.717 kpc at a distance of R = [19.5, 20] kpc, which is almost twice as high as the amplitude of the whole population of the disc. We find a significant flare of the whole population, especially in the thick disc. The scale height increases from h z,thick ≈ 0.8 kpc and h z,thin ≈ 0.3 kpc in the solar neighbourhood, to h z,thick ≈ 3 kpc and h z,thin ≈ 0.7 kpc in the remote regions of the Milky Way (R ≈ 18 kpc). The supergiants' population has only a small flare.

show abstract

“…In order to convert the interstellar reddening of these maps into E(B − V), we used the coefficients (Hendy 2018;Rybizki et al 2018):…”

Section: Extinction Mapmentioning

confidence: 99%

Warp and flare of the Galactic disc revealed with supergiants by Gaia EDR3

Chrobáková

Nagy

López-Corredoira

2022

A&A

View full text Add to dashboard Cite

show abstract

“…This map combines the results of Marshall et al (2006), Green et al (2015), and Drimmel et al (2003) and provides reddening as defined in Schlegel et al (1998). In order to convert the interstellar reddening of these maps into E(B − V ), we used coefficients (Hendy 2018;Rybizki et al 2018)…”

Section: Extinction Mapsmentioning

confidence: 99%

Structure of the outer Galactic disc with Gaia DR2

Chrobáková

Nagy

López-Corredoira

2020

A&A

View full text Add to dashboard Cite

Context. The structure of outer disc of our Galaxy is still not well described, and many features need to be better understood. The second Gaia data release (DR2) provides data in unprecedented quality that can be analysed to shed some light on the outermost parts of the Milky Way. Aims. We calculate the stellar density using star counts obtained from Gaia DR2 up to a Galactocentric distance R=20 kpc with a deconvolution technique for the parallax errors. Then we analyse the density in order to study the structure of the outer Galactic disc, mainly the warp. Methods. In order to carry out the deconvolution, we used the Lucy inversion technique for recovering the corrected star counts. We also used the Gaia luminosity function of stars with MG < 10 to extract the stellar density from the star counts. Results. The stellar density maps can be fitted by an exponential disc in the radial direction hr = 2.07 ± 0.07 kpc, with a weak dependence on the azimuth, extended up to 20 kpc without any cut-off. The flare and warp are clearly visible. The best fit of a symmetrical S-shaped warp gives zw ≈ z + (37 ± 4.2(stat.) − 0.91(syst.))pc · (R/R ) 2.42±0.76(stat.)+0.129(syst.) sin(φ + 9.3 • ± 7.37 • (stat.) + 4.48 • (syst.)) for the whole population. When we analyse the northern and southern warps separately, we obtain an asymmetry of an ∼ 25% larger amplitude in the north. This result may be influenced by extinction because the Gaia G band is quite prone to extinction biases. However, we tested the accuracy of the extinction map we used, which shows that the extinction is determined very well in the outer disc. Nevertheless, we recall that we do not know the full extinction error, and neither do we know the systematic error of the map, which may influence the final result. The analysis was also carried out for very luminous stars alone (MG < −2), which on average represents a younger population. We obtain similar scale-length values, while the maximum amplitude of the warp is 20 − 30% larger than with the whole population. The north-south asymmetry is maintained.

show abstract

“…This method has been previously used by Bisht et al (2018) for OCs Teutsch 10 and Teutsch 25. Hendy (2018) used this method for the open cluster FSR 814. The kinematical probability of stars is expressed as:…”

Section: Proper Motion Study and Membership Probabilities Of Starsmentioning

confidence: 99%

Study of an Intermediate Age Open Cluster Ic 1434 Using Ground-Based Imaging and Gaia Dr2 Astrometry

Hendy

Bisht

2021

RMxAA

View full text Add to dashboard Cite

We present a detailed photometric and kinematical analysis of the poorly studied open cluster IC 1434 using CCD VRI, APASS, and Gaia DR2 database for the first time. By determining the membership probability of stars we identify the 238 most probable members with a probability higher than 60%; by using proper motion and parallax data as taken from the Gaia DR2 catalog. The mean proper motion of the cluster is obtained as μx=−3.89±0.19 and μy=−3.34±0.19 mas yr−1 in both the directions of right ascension and declination. The radial distribution of member stars provides the cluster extent as 7.6 arcmin. We estimate the interstellar reddening E(B−V) as 0.34 mag using the transformation equations from the literature. We obtain the values of cluster age and distance as 631±73 Myr and 3.2±0.1 kpc.

show abstract

BVR photometric investigation of galaxy pair KPG 562

Cited by 6 publications

References 15 publications

Warp and flare of the Galactic disc revealed with supergiants by Gaia EDR3

Warp and flare of the Galactic disc revealed with supergiants by Gaia EDR3

Structure of the outer Galactic disc with Gaia DR2

Study of an Intermediate Age Open Cluster Ic 1434 Using Ground-Based Imaging and Gaia Dr2 Astrometry

Contact Info

Product

Resources

About