Kinematics and multiband period–luminosity–metallicity relation of RR Lyrae stars via statistical parallax

ABSTRACT This paper presents results from photometric and statistical-parallax analysis of a sample of 850 field RR Lyrae (RRL) variables. The photometric and spectroscopic data for our sample of RRLs are obtained from (1) our new spectroscopic observations (for 448 RRLs) carried out with the Southern African Large Telescope; (2) our photometric observations using the 1.0-m telescope of the South African Astronomical Observatory, and (3) literature. These are combined with accurate proper motion data from the second data release of the Gaia mission (DR2). This study primarily determines the velocity distribution of solar neighbourhood RRLs, and it also calibrates the zero-points of the RRLs’ visual V-band luminosity–metallicity (LZ or MV–[Fe/H]) relation and their period–luminosity–metallicity (PLZ) relations in the Wide-field Infrared Survey ExplorerW1 and Two-Micron All-Sky Survey Ks bands. We find the bulk velocity of the halo RRLs relative to the Sun to be (U0, V0, W0)Halo =(− 16 ± 7, −219 ± 7, −6 ± 5) km s−1 in the direction of Galactic centre, Galactic rotation, and North Galactic pole, respectively, with velocity-dispersion ellipsoids (σVR, σVϕ, σVθ)Halo = (153 ± 7, 106 ± 4, 101 ± 4) km s−1. The corresponding parameters for the disc component are found to be (U0, V0, W0)Disc = (− 19 ± 5, −46 ± 5, −14 ± 3) km s−1 and (σVR, σVϕ, σVθ)Disc =(49 ± 4, 38 ± 4, 25 ± 3) km s−1. The calibrated PLZ in W1-, Ks-, and V-band LZ relations are $\langle \, M_{W1}\rangle =$ $-0.824+0.124[\mathrm{ Fe/H}]-2.381\log \, P_F$, 〈MKs〉 = $-0.804+0.101[\mathrm{ Fe/H}]-2.33\log \, P_F$, and $\langle \, M_V\rangle =1.041+0.232[\mathrm{ Fe/H}]$, respectively. The calibrated PLZ and LZ relations are used to estimate the Galactic Centre distance and the distance modulus of the Large Magellanic Cloud (LMC), which are found to be 7.99 ± 0.49 kpc and 18.46 ± 0.09 mag, respectively. All our results are in excellent agreement with available literature based on statistical-parallax analysis, but are considerably more accurate and precise. Moreover, the zero-points of our calibrated PLZ and LZ relations are quite consistent with current results found by other techniques and yield an LMC distance modulus that is within 0.04 mag of the current most precise estimate.

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Standard Galactic field RR Lyrae II: a Gaia DR2 calibration of the period–Wesenheit–metallicity relation

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stz2814 ◽

2019 ◽

Vol 490 (3) ◽

pp. 4254-4270 ◽

Cited By ~ 4

Author(s):

Jillian R Neeley ◽

Massimo Marengo ◽

Wendy L Freedman ◽

Barry F Madore ◽

Rachael L Beaton ◽

...

Keyword(s):

Near Infrared ◽

Large Magellanic Cloud ◽

Magellanic Cloud ◽

Distance Modulus ◽

Rr Lyrae Stars ◽

Galactic Field ◽

Rr Lyrae ◽

Lyrae Stars ◽

Distance Indicators ◽

Made In

ABSTRACT RR Lyrae stars have long been popular standard candles, but significant advances in methodology and technology have been made in recent years to increase their precision as distance indicators. We present multiwavelength (optical UBVRcIc and Gaia G, BP, RP; near-infrared JHKs; mid-infrared [3.6], [4.5]) period–luminosity–metallicity (PLZ), period–Wesenheit–metallicity (PWZ) relations, calibrated using photometry obtained from the Carnegie RR Lyrae Program and parallaxes from the Gaia second data release for 55 Galactic field RR Lyrae stars. The metallicity slope, which has long been predicted by theoretical relations, can now be measured in all passbands. The scatter in the PLZ relations is on the order of 0.2 mag, and is still dominated by uncertainties in the parallaxes. As a consistency check of our PLZ relations, we also measure the distance modulus to the globular cluster M4, the Large Magellanic Cloud and the Small Magellanic Cloud, and our results are in excellent agreement with estimates from previous studies.

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The distance to the Large Magellanic Cloud from first overtone RR Lyrae variables

International Astronomical Union Colloquium ◽

10.1017/s0252921100010587 ◽

2004 ◽

Vol 193 ◽

pp. 180-183

Author(s):

A.V. Muzzin ◽

C.M. Clement ◽

D.R. Alves ◽

Keyword(s):

Fourier Coefficients ◽

Large Magellanic Cloud ◽

Light Curves ◽

Log P ◽

Distance Modulus ◽

P Values ◽

Rr Lyrae ◽

Visual Distance ◽

Bona Fide ◽

Absolute Magnitudes

AbstractFourier coefficients have been derived for the V and R light curves of 330 bona fide RR Lyrae first-overtone (RR1) pulsators in 16 MACHO fields near the bar of the LMC. We use the Fourier phase parameter ɸ31 and log P values to select a subsample of these stars which are similar to the RR1s in the Galactic globular cluster M5. Assuming that the M5-like stars in the LMC have absolute magnitudes comparable to the HB stars in M5, we use independent studies to derive their mean absolute V magnitude and compute a visual distance modulus of μLMC = 18.43 ± 0.06 (statistical) ±0.16 (systematic). By selecting stars on the basis of their light curve parameters, we are able to derive a distance modulus that does not depend on the somewhat poorly determined Mv – [Fe/H] relation for RR Lyr stars.

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Calibration of the Cepheid Distance Scale

International Astronomical Union Colloquium ◽

10.1017/s0252921100116926 ◽

1993 ◽

Vol 139 ◽

pp. 72-80

Author(s):

Wolfgang P. Gieren ◽

Pascal Fouqué

Keyword(s):

Large Magellanic Cloud ◽

Distance Scale ◽

Absolute Calibration ◽

Rr Lyrae Stars ◽

Sn 1987A ◽

Rr Lyrae ◽

Calibration Sets ◽

Lyrae Stars ◽

Zero Points ◽

Good Agreement

AbstractThe absolute calibration of the Cepheid period-luminosity (PL) relation with galactic Cepheids is discussed. Various methods, most importantly the cluster ZAMS-fitting scale and the Baade-Wesselink scale are found to yield PL zero points which agree within ∼ ± 0.1 mag. The present Cepheid calibration sets the Large Magellanic Cloud at μ0 (LMC) = 18.6 ± 0.1 mag, in good agreement with the distance derived from SN 1987A and other methods except RR Lyrae stars which seem to give a shorter distance scale.

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Maximum Magnitude Vs. Rate of Decline for Novae of the LMC

International Astronomical Union Colloquium ◽

10.1017/s0252921100068408 ◽

1990 ◽

Vol 122 ◽

pp. 71-72

Author(s):

M. Capaccioli ◽

M. Della Valle ◽

M. D’Onofrio ◽

L. Rosino

Keyword(s):

Close Agreement ◽

Large Magellanic Cloud ◽

Magellanic Cloud ◽

Distance Modulus ◽

Maximum Magnitude ◽

Rr Lyrae ◽

Rate Of Decline

AbstractWe derive the distance modulus of the Large Magellanic Cloud (LMC) by applying the new calibrated relationship between maximum magnitude and rate of decline (MMRD). The result, , is in close agreement with the most recent determinations based on RR Lyrae and Cepheids. We also discuss the properties of the MMRD of M31 and of the LMC.

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Calibration En Magnitudes Absolues De La Classification BCD. Application à La Détermination Du Module De Distance Du Grand Nuage De Magellan

Symposium - International Astronomical Union ◽

10.1017/s007418090005511x ◽

1973 ◽

Vol 54 ◽

pp. 78-85

Author(s):

L. Divan

Keyword(s):

Large Magellanic Cloud ◽

Magellanic Cloud ◽

Distance Modulus ◽

Rr Lyrae ◽

A Value ◽

Cepheid Variables ◽

Absolute Magnitudes

The calibration of the BCD stellar classification in absolute magnitudes (classification in three parameters λ1, D, Φb) was used to determine the distance modulus of the Large Magellanic Cloud. The described method makes use of the spectrophotometric parameters of B and A supergiants of the Large Cloud and gives a value of the distance modulus which is independent from other determinations, in particular from those which are based on the RR Lyrae and the Cepheid variables. The value found for the distance is slightly smaller than those generally admitted. The results are still based only on a limited number of measurements and new observations are in process; however, it seems doubtful that one will obtain much larger values. In other respects, the observations have shown that the parameter λ1 was still sensitive to luminosity for the B and A stars brighter than M = −8 and that the calibration of the λ1D diagram in absolute magnitudes can be extended up to M = −9.

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Classical Cepheids, what else?

Proceedings of the International Astronomical Union ◽

10.1017/s1743921312021229 ◽

2012 ◽

Vol 8 (S289) ◽

pp. 116-125 ◽

Cited By ~ 1

Author(s):

G. Bono ◽

L. Inno ◽

N. Matsunaga ◽

K. Genovali ◽

B. Lemasle ◽

...

Keyword(s):

Surface Brightness ◽

Near Infrared ◽

Large Magellanic Cloud ◽

Magellanic Cloud ◽

Distance Modulus ◽

Period Range ◽

Classical Cepheids ◽

Similar Distance ◽

Distance Indicators ◽

Zero Points

AbstractWe present new and independent estimates of the distances to the Magellanic Clouds (MCs) using near-infrared (NIR) and optical–NIR period–Wesenheit (PW) relations. The slopes of the PW relations are, within the dispersion, linear over the entire period range and independent of metal content. The absolute zero points were fixed using Galactic Cepheids with distances based on the infrared surface-brightness method. The true distance modulus we found for the Large Magellanic Cloud—(m − M)0 = 18.48 ± 0.01 ± 0.10 mag—and the Small Magellanic Cloud—(m − M)0 = 18.94 ± 0.01 ± 0.10 mag—agree quite well with similar distance determinations based on robust distance indicators. We also briefly discuss the evolutionary and pulsation properties of MC Cepheids.

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The Distance to the Large Magellanic Cloud

International Astronomical Union Colloquium ◽

10.1017/s0252921100057547 ◽

2000 ◽

Vol 176 ◽

pp. 203-207

Author(s):

Piotr Popowski

Keyword(s):

Galactic Center ◽

Large Magellanic Cloud ◽

Magellanic Cloud ◽

Distance Modulus ◽

Local Universe ◽

Rr Lyrae Stars ◽

Rr Lyrae ◽

Red Clump ◽

Lyrae Stars ◽

Selective Extinction

AbstractI demonstrate that the two unexpected results in the local Universe: anomalous intrinsic (V – I)0 colors of RR Lyrae stars and clump giants in the Galactic center, and very short distances to Magellanic Clouds inferred from clump giants, can be at least partially resolved with a modified coefficient of selective extinction AV/E(V – I). With this modification, I find a new clump-giant distance modulus to the Large Magellanic Cloud, μLMC = 18.27 ± 0.07, which is 0.09 larger than the Udalski (1998b) result. When distance estimates from the red clump, RR Lyrae stars and the eclipsing binary HV2274 are combined, one obtains μLMC = 18.31 ± 0.04 (internal).

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Calibrating the BHB star distance scale and the halo kinematic distance to the Galactic Centre

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa2819 ◽

2020 ◽

Vol 499 (1) ◽

pp. 1058-1071

Author(s):

Nikita D Utkin ◽

Andrei K Dambis

Keyword(s):

Velocity Dispersion ◽

Anisotropy Parameter ◽

Galactic Centre ◽

Galactic Rotation ◽

Galactocentric Distance ◽

Absolute Value ◽

Dispersion Tensor ◽

Rr Lyrae ◽

Parameter Values

ABSTRACT We report the first determination of the distance to the Galactic Centre based on the kinematics of halo objects. We apply the statistical-parallax technique to the sample of ∼2500 blue horizontal branch (BHB) stars compiled by Xue et al. to simultaneously constrain the correction factor to the photometric distances of BHB stars as reported by those authors and the distance to the Galactic Centre to find R = 8.2 ± 0.6 kpc. We also find that the average velocity of our BHB star sample in the direction of Galactic rotation, V0 = −240 ± 4 km s−1, is greater by about 20 km s−1 in absolute value than the corresponding velocity for halo RR Lyrae type stars (V0 = −222 ± 4 km s−1) in the Galactocentric distance interval from 6 to 18 kpc, whereas the total (σV) and radial (σr) velocity dispersion of the BHB sample are smaller by about 40–45 km s−1 than the corresponding parameters of the velocity dispersion ellipsoid of halo RR Lyrae type variables. The velocity dispersion tensor of halo BHB stars proved to be markedly less anisotropic than the corresponding tensor for RR Lyrae type variables: the corresponding anisotropy parameter values are equal to βBHB = 0.51 ± 0.02 and βRR = 0.71 ± 0.03, respectively.

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Distance to SN 1987A and the LMC

Symposium - International Astronomical Union ◽

10.1017/s0074180900118959 ◽

1999 ◽

Vol 190 ◽

pp. 549-554

Author(s):

Nino Panagia

Keyword(s):

Angular Size ◽

Large Magellanic Cloud ◽

Magellanic Cloud ◽

Light Curves ◽

Distance Modulus ◽

Absolute Size ◽

Sn 1987A

Using the new reductions of the IUE light curves by Sonneborn et al. (1997) and an extensive set of HST images of SN 1987A we have repeated and improved Panagia et al. (1991) analysis to obtain a better determination of the distance to the supernova. In this way we have derived an absolute size of the ringRabs= (6.23 ± 0.08) x 1017cm and an angular sizeR″ = 808 ± 17 mas, which give a distance to the supernovad(SN1987A) = 51.4 ± 1.2 kpc and a distance modulusm–M(SN1987A) = 18.55 ± 0.05. Allowing for a displacement of SN 1987A position relative to the LMC center, the distance to the barycenter of the Large Magellanic Cloud is also estimated to bed(LMC) = 52.0±1.3 kpc, which corresponds to a distance modulus ofm–M(LMC) = 18.58±0.05.

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