The Kinematics and Zero Point of the log P -- <M_K> Relation for Galactic Field RR Lyrae Variables via Statistical Parallax

Details The Kinematics and Zero Point of the log P -- <M_K> Relation for Galactic Field RR Lyrae Variables via Statistical Parallax The Kinematics and Zero Point of the log P -- <M_K> Relation for Galactic Field RR Lyrae Variables via Statistical Parallax

2003-03-20

arxiv.org/abs/astro-ph/0303463v1

Astronomy and Astrophysics

Astrophysics

6 pages, to appear in "Galatic Dynamics", eds. C. Boily, P. Patsis, C. Theis, S. Portegies Zwart, R. Spurzem, EDP Sciences 200

Scientific paper

The kinematical parameters of the local field RR Lyrae population and the zero point of the log P-- relation for these variables are inferred by applying the statistical parallax (maximum-likelihood) technique to a sample of 182 RR Lyraes with known periods, radial-velocities, metallicities, K-band photometry, and absolute proper motions on the ICRS system. The K-band magnitudes were adopted from the list of Fernley et al. (1998) and the 2MASS Second Incremental Data Release. The parameters of the velocity distribution are found to be (U_0,V_0,W_0) = (-10 +/- 10, -51 +/- 8, -14 +/- 5) km/s, (sigma_U, sigma_V, sigma_W) = (62 +/- 10, 45 +/- 8, 28 +/- 6) km/s and (U_0,V_0,W_0) = (-23 +/- 13, -213 +/- 12, -5 +/- 8) km/s, (sigma_U, sigma_V, sigma_W) = (157 +/- 12, 98 +/- 8, 91 +/- 7) km/s for the thick-disk (41 stars) and halo (141 stars) objects, respectively. The zero point of the infrared PL relation of Jones et al. (1992) (based on the results obtained using the Baade-Wesselink method) is confirmed: we find = -2.33 log P_F-0.82 +/- 0.12 compared to = -2.33 log P_F-0.88 as inferred by Jones et al. (1992). A conversion of the resulting log P- relation to V-band luminosities yields the metallicity-luminosity relation = +1.04 + 0.14 [Fe/H] +/- 0.11. Our results imply a solar Galactocentric distance of R_0 = 7.6 +/- 0.4 kpc and an LMC distance modulus of DM_LMC = 18.18 +/- 0.12 (cluster RR Lyraes) or DM_LMC = 18.11 +/- 0.12 (field RR Lyraes), thereby favoring the so-called short distance scale.

Affiliated with

Also associated with

No associations

Rating

The Kinematics and Zero Point of the log P -- <M_K> Relation for Galactic Field RR Lyrae Variables via Statistical Parallax does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with The Kinematics and Zero Point of the log P -- <M_K> Relation for Galactic Field RR Lyrae Variables via Statistical Parallax, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Kinematics and Zero Point of the log P -- <M_K> Relation for Galactic Field RR Lyrae Variables via Statistical Parallax will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-205304