Extragalactic Distance Indicators Research Articles

Bias Properties of Extragalactic Distance Indicators. VII. Correlation of Absolute Luminosity and Rotational Velocity for S[CSC]c[/CSC] Galaxies over the Range of Luminosity Class from I to III–IV

A distance-limited subset of the complete flux-limited sample of Sc galaxies in the Revised Shapley-Ames Catalog of Bright Galaxies is isolated by means of separate Spaenhauer diagrams for six individual van den Bergh luminosity class intervals from Sc I + I.2, .3 to Sc III–IV. The distribution functions of kinematic absolute B(220, 50) magnitudes and 21 cm line widths, W20, corrected to edge-on orientation, have been determined for the same six bins of luminosity class. The individual luminosity functions for each luminosity class are bounded on both the bright and faint ends, showing that the present sample includes no dwarf Sc spirals fainter than M(BT)(220, 50) = -18 belonging to luminosity classes I to III–IV, as defined by the regularity of the spiral pattern. Star-forming galaxies with spiral structures as regular as the ones found in these luminosity classes have absolute magnitudes brighter than MB(H = 50) = -18 and 21 cm line widths larger than W20/ sin i = 2vrot(max) = 165 km s-1. Furthermore, the 21 cm line-width distributions move toward smaller rotational velocities as the luminosity classes change from I to III, showing that rotation is a principal parameter determining the regularity of the spiral pattern. Whether it is the only parameter awaits a similar investigation for spirals of all luminosity classes along the complete Hubble sequence. In particular, it has not yet been proved that all Im and Sm galaxies, where, by definition, the spiral arms are either lacking or are semichaotic, have absolute magnitudes that are fainter than MB = -18 and whose 21 cm LWs are smaller than ~165 km s-1, presumably because of smaller mass than the high-luminosity, regular spirals. The Teerikorpi cluster population incompleteness bias is demonstrated again. Here, however, as in Papers II–IV of this series, we use field galaxies to show that the slope and zero point of the Tully-Fisher (T-F) relation are systematically incorrect for flux-limited samples, the error increasing with redshift. The data also support the possibility that the zero point of the T-F relation for Sc galaxies, even in the distance-limited sample, is a function of luminosity class, varying by 0.42 mag between Sc I + I.2, .3 and Sc III galaxies if the slope of the T-F relation for each class is taken to be that of the fundamental calibrating galaxies with Cepheid distances. If true, this is presumably due to differences in the mass distribution and, therefore, in the resulting rotational velocity field as a function of luminosity class even within a fixed Hubble type.

Calibration of the Faber-Jackson relation for M31 globular clusters using Hipparcos data

In this paper we present a data analysis regarding globular clusters as possible extragalactic distance indicators. For this purpose, we collected all velocity dispersion measurements published for galactic and M31 globular clusters. The slope and the zero-point of the Faber-Jackson relation were calibrated using Hipparcos distance measurements, and the relation was applied to extragalactic globular clusters in M31. A distance modulus of 24.12 \pm 0.45 mag was found. This is coherent with what is found by fitting the red giant branches of globular clusters (24.47 \pm 0.07, Holland 98), and is found from the peak of globular clusters luminosity function (24.03 \pm 0.23, Ostriker an d Gnedin 97), but shorter than the 24.7 \pm 0.2 mag (Lanoix et al. 98) and 24.77 \pm 0.11 mag (Feast and Catchpole 97), obtained by using Hipparcos data to calibrate the Cepheid period-luminosity. This calibrated Faber-Jackson relation can now be directly use for other Sc galaxies with resolved globular clusters, as soon as large amounts of spectra will become available, e.g., through the VLT.

Tip of the Red Giant Branch Distances to Galaxies. IV. Sextans B

We present color-magnitude diagrams and luminosity functions of stellar populations in the nearby dwarf galaxy Sextans B, based on VI photometry acquired with the Carnegie Observatories spectroscopic multislit and imaging camera CCD prime-focus camera on the Palomar 5 m telescope. Combining previously published Cepheid observations with our new data, we obtain a distance to Sextans B based on the multiwavelength period-luminosity (PL) relations; BVRI data for eight Cepheids having periods ranging from 4 to 30 days were used. This Population I true distance modulus for Sextans B is found to be (m - M)0 = 25.69 ± 0.27 mag (1.37 ± 0.18 Mpc) with an extinction value of AV = 0.05 mag. The Cepheid distance is then compared with the Population II distance, determined by applying the tip of the red giant branch (TRGB) method. A discontinuity in the I-band luminosity function is detected at I = 21.60 ± 0.10 mag. Adopting MI = -4.04 ± 0.02 mag as the absolute magnitude of the TRGB, and taking into account the Galactic extinction value of AI = 0.02 mag, we obtain a Population II distance modulus of (m - M)0 = 25.56 ± 0.10 mag (1.29 ± 0.07 Mpc). Additional systematic uncertainties in the TRGB distance scale probably exist at the 5%-10% level. The agreement between the two distances and their uncertainties derived from distinctly independent methods further demonstrates that the accuracy and precision of the TRGB method as an extragalactic distance indicator are comparable to those of the Cepheid PL relation.

A new distance criterion for spirals in the zone of avoidance

The classical Tully-Fisher (TF) relation, used to derive distances of spiral galaxies, is not suitable in the zone of avoidance. We show that it is possible to use another form, the 21 cm Tully-Fisher relation (TF21), using only HI data. Our 4867 galaxy KLUN sample (from Nançay observations, and LEDA database) allows us to derive its slope, the zero point being fixed with a set of 18 primary calibrators: a = 1.430 ± 0.030, b = 6.45 ± 0.07, σ= 0.264 for the relation log ( M HI /m ⊙ ) = a × log ( V M ) + b. The actual uncertainty on derived distances is roughly 30%; we expect that this scatter, and consequently the Malmquist bias effect, may be reduced by considering separately the different types. The TF21 relation appears usable to obtain distances in the zone of avoidance, and is expected to provide a competitive extragalactic distance indicator.

Bias Properties of Extragalactic Distance Indicators. V.Ho From Luminosity Functions of Different Spiral Types and Luminosity Classes Corrected for Bias

view Abstract Citations (26) References (98) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Bias Properties of Extragalactic Distance Indicators. V. H0 From Luminosity Functions of Different Spiral Types and Luminosity Classes Corrected for Bias Sandage, Allan Abstract The method originally used by Lemaitre (1927, 1931), Robertson (1928), Hubble (1929b), and Hubble & Humason (1931) to determine the Hubble constant at H0 ~ 500 km s^-1^ Mpc^-1^ is used again here with modern data. The refinements introduced by van den Bergh (1960a,b) and de Vaucouleurs (1979a,b) of binning the galaxies separately by Hubble type and luminosity class to narrow the dispersions of the individual luminosity functions, are adopted. The mean absolute magnitudes, <M(m,T,L)>, of galaxies of types Sb, Sbc, and Sc in the flux-limited RSA2 catalog varies systematically with luminosity class (L), as van den Bergh had originally demonstrated in his discovery papers. Arguments are given why the absolute magnitudes calculated from redshifts, used here, are more reliable than photometric distances derived in other ways. The local velocity field (v < 4000 km s^-1^) is remarkably quiet when corrected to the Virgocentric frame. Corrections to change the flux-limited luminosity functions to bias-free mean absolute magnitudes for distance-limited samples, <M(o,T,L)>+5 log(H0/50), are set out in tables. An absolute calibration of the relative luminosities is made using 11 local galaxies of known distance, giving H0 = 56+/-5 km s^-1^ Mpc^-1^. If an analysis had been made that ignored the correction for observational selection bias, an incorrect Hubble constant of 72+/-5 would have been obtained. To make H0 ~ 85 as advocated by many proponents of the short distance scale, would require that our present mean absolute magnitude zero point would have to differ from that of the short scale by 0.91 mag, which is a ~5 σ(M) error, showing that the short distance scale is impossible if the distances to the calibrators adopted here are correct. Publication: The Astronomical Journal Pub Date: January 1996 DOI: 10.1086/117755 Bibcode: 1996AJ....111....1S Keywords: DISTANCE SCALES; GALAXIES: PHOTOMETRY; GALAXIES: DISTANCES AND REDSHIFTS full text sources ADS | data products SIMBAD (14) NED (11) Related Materials (10) Part 1: 1994ApJ...430....1S Part 2: 1994ApJ...430...13S Part 3: 1994ApJ...430...29F Part 4: 1995ApJ...452....1S Part 6: 1996AJ....111...18S Part 7: 1999AJ....117..157S Part 8: 1999ApJ...527..479S Part 9: 2000PASP..112..504S Part 10: 2002AJ....123.1179S Part 11: 2002AJ....123.2047S

Bias Properties of Extragalactic Distance Indicators. VI. Luminosity Functions of M31 and M101 Look-alikes Listed in the RSA2: H0 Therefrom

Bias Properties of Extragalactic Distance Indicators. VI. Luminosity Functions of M31 and M101 Look-alikes Listed in the RSA2: H0 Therefrom

Bias Properties of Extragalactic Distance Indicators. IV. Demonstration of the Population Incompleteness Bias Inherent in the Tully-Fisher Method Applied to Clusters

view Abstract Citations (55) References (39) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Bias Properties of Extragalactic Distance Indicators. IV. Demonstration of the Population Incompleteness Bias Inherent in the Tully-Fisher Method Applied to Clusters Sandage, Allan ; Tammann, G. A. ; Federspiel, Martin Abstract A demonstration is made of the existence of the Teerikorpi Cluster Population Incompleteness Bias (CPIB) in the Tully-Fisher (TF) method of distance determination. A bias exists if the cluster is sampled incompletely into its luminosity function, despite the fact that all the cluster galaxies are at nearly the same distance. Neglect of the bias will give too small a cluster distance and, therefore, too high a Hubble constant. The bias is modeled using graphical methods based on properties of Spaenhauer diagrams following the method of Papers II and III. It is shown that the bias is the same as the individual Msun M(m, z) corrections derived in Paper I, generalized to the M0- M(m, Vrot,Z) corrections in Papers II and III for the TF method. Four predictions of the model are that (1) the slope of the apparent TF regression depends on how far we sample into the cluster luminosity function, (2) the highest rotators will lie closest to the unbiased fiducial TF ridge line, (3) the error in the distance modulus decreases as the magnitude grasp into the cluster luminosity function (LF) increases, reaching zero only at ∼6 mag into the cluster LF if the intrinsic dispersion is as high as we obtain here, and (4) the observed, not the true, dispersion is a strong function of the sampling depth into the luminosity function. The small TF dispersions in clusters derived in a number of current discussions are artifacts of the bias caused by using incomplete samples. The predictions are verified using two independent data samples of real galaxies. Values of the Hubble constant near H0 = 90 km s-1 Mpc-1 found using incomplete cluster data reduce to unbiased values between 45 and 55 when corrections for the cluster incompleteness bias are applied. Publication: The Astrophysical Journal Pub Date: October 1995 DOI: 10.1086/176275 Bibcode: 1995ApJ...452....1S Keywords: COSMOLOGY: DISTANCE SCALE; GALAXIES: DISTANCES AND REDSHIFTS; METHODS: STATISTICAL full text sources ADS | data products SIMBAD (16) Related Materials (10) Part 1: 1994ApJ...430....1S Part 2: 1994ApJ...430...13S Part 3: 1994ApJ...430...29F Part 5: 1996AJ....111....1S Part 6: 1996AJ....111...18S Part 7: 1999AJ....117..157S Part 8: 1999ApJ...527..479S Part 9: 2000PASP..112..504S Part 10: 2002AJ....123.1179S Part 11: 2002AJ....123.2047S

Globular Cluster Systems as Distance Indicators Metallicity Effects on the Luminosity Function

We investigate the universality of the globular cluster luminosity function (GCLF) and the use of this function as an extragalactic distance indicator. Previous studies have found an offset between GCLF distances and those obtained with other techniques. We show that this offset can be understood in terms of a metallicity effect. Specifically, the globular cluster systems used in distance scale studies have traditionally been those around elliptical galaxies. These systems have higher mean metallicities than the Milky Way globular cluster system. Consequently, the peak of the GCLF in the systems around ellipticals is significantly fainter in $B$ and $V$ than the GCLF peak in the Milky Way. We calculate the shift in the peak of the GCLF relative to the Milky Way globulars in $B$, $V$, $R$, $I$ and $J$ for a range of globular cluster metallicities. Applying these corrections, we find good agreement between GCLF distances and those obtained using the surface brightness fluctuations method. The similarity between metallicity-corrected GCLFs suggests that the underlying mass function of globular cluster systems is remarkably constant from one galaxy to another. Our results allow the GCLF to be employed as an improved distance indicator.

Some studies of galactic and extragalactic distance scales

A review is given of some aspects of work in South Africa on the establishment, calibration and use of galactic and extragalactic distance indicators.

Bias properties of extragalactic distance indicators. 2: Bias corrections to Tully-Fisher distances for field galaxies

Bias properties of extragalactic distance indicators. 2: Bias corrections to Tully-Fisher distances for field galaxies

Bias properties of extragalactic distance indicators. 1: The Hubble constant does not increase outward

Bias properties of extragalactic distance indicators. 1: The Hubble constant does not increase outward

A new extragalactic distance indicator based on the surface brightness profiles of dwarf elliptical galaxies

A new extragalactic distance indicator based on the surface brightness profiles of dwarf elliptical galaxies

The Cepheid Period-Luminosity Relation from Independent Distances of 100 Galactic Variables

view Abstract Citations (86) References (78) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The Cepheid Period-Luminosity Relation from Independent Distances of 100 Galactic Variables Gieren, Wolfgang P. ; Barnes, Thomas G., III ; Moffett, Thomas J. Abstract We have determined distances to 100 galactic classical Cepheids on a homogeneous system with an improved version of the surface brightness technique, using the extensive northern Cepheid observations of Moffett and Barnes, and the southern Cepheid observations of Gieren. The period-luminosity relations in the V bandpass obtained for the northern and southern Cepheid samples are found consistent, and the absolute magnitudes have been combined into a two-hemisphere PL(V) relation which is Mv= -1.371 -2.986 log P. ±0.095 ±0.094 This is the currently most precise Cepheid PL(V) relation from the surface brightness technique. Typically Mv can be obtained from this relation for Cepheids with periods in the range 3 to 45 days to better than ±0.06 mag, if all the scatter in the relation is observational, or ±0.27 mag, if all the scatter is cosmic in origin. We compare our result to other recent observational determinations of the PL(V) relation and find consistency among the results produced by the surface brightness method, main-sequence fitting of open clusters and associations containing Cepheids, Hβ photometry, and statistical parallaxes. In particular, there is no significant difference between the surface brightness and ZAMS-fitting Cepheid distance scales. The agreement between the ZAMS-fitting distance scale and the fully independent surface brightness distance scale provides extremely persuasive evidence that both methods are free of significant systematic errors at the ±0.10 mag level. We show that there is no significant correlation between the residuals of the Mv from the PL(V) relation and the residuals of the intrinsic (B - V) colors of the Cepheids from the mean period-color relation, making it impossible to find a PLC relation from our data. After correcting the Cepheid distances for the small, theoretically predicted metallicity dependence of the surface brightness technique, we find no significant trend in the Mv residuals from our PL(V) relation with the galactocentric distances of the Cepheids. While the Cepheids become intrinsically bluer as their radial distances from the Galactic center increase, their mean absolute magnitudes, at a given period, do not depend on their galactocentric distances at a significant level, which is an important property in view of the use of Cepheid variables as extragalactic distance indicators. Publication: The Astrophysical Journal Pub Date: November 1993 DOI: 10.1086/173377 Bibcode: 1993ApJ...418..135G Keywords: COSMOLOGY: DISTANCE SCALE; STARS: OSCILLATIONS; STARS: VARIABLES: CEPHEIDS full text sources ADS | data products SIMBAD (100) NED (1)

The dependence of the brightness fluctuation distance indicator on stellar population age and metallicity

We describe how the extragalactic distance indicator L depends on stellar population age, metallicity, and IMF, assuming single-burst ages between 5 and 17 Gyr and metallicities between −0.5 and +0.5 dex. We consider Johnson/Cousins BVR C l C JHKLL'M passbands. We find that (1) L is insensitive to changes in IMF, (2) L can be reliably calibrated against colors or spectral indices, due to the similarity of the effects of age and metallicity on the stellar populations, (3) the calibration presented here may already give distances good to 10% for an isolated galaxy measured in one fluctuation passband and one color or spectral index, not including observational error, and (4) our theoretical results are consistent with the distance of M32 and with the latest empirical Ī calibration and require no empirical corrections

TUNING THE CEPHEID DISTANCE SCALE

ABSTRACT With the advent of a number of promising new secondary extragalactic distance indicators, the reliaable calibration of the Cepheid distance scale becomes increasingly imperative. Ongoing observational programs (both from the ground and space) promise to provide a significantly larger sample of galaxies with well-studied Cepheids both within the Local Group and in more distant galaxies. In this review I describe recent efforts in the calibration of the Cepheid distance scale using Cepheids in star clusters in the Galaxy and in the Magellanic Clouds. I emphasize some of the important advantages of using LMC Cepheids in particular, and summarize the current status of the field. Some of the complications involved in the methods discussed to calibrate the Cepheid distance scale are also described along with suggestions for future work.

THE CEPHEID DISTANCE SCALE

ABSTRACT classical Cepheids are discussed with particular emphasis on the fact that Cepheids continue to provide the most homogeneous and reliable set of distances to many nearby galaxies. Observational programs relating to extragalactic Cepheids are also reviewed, and new distances and reddenings to individual galaxies are determined from these data using multiwavelength PL relations, based for the first time on self-consistent calibrating data sets. Three recent promising secondary extragalactic distance indicators (Tully-Fisher, planetary nebula luminosity functions, and surface-brightness fluctuations) tie their zero points to the Cepheid distance scale and give globally consistent values for the Hubble constant of about 80 km sec-1^ Mpc-1^. Tying the Faber-Jackson relation and the supernova distance scales to the Leo and Virgo clusters yields similar results. Such a value for the Hubble constant is marginally inconsistent with new estimates of the ages of globular clusters, and it may prove to be a serious problem for standard cold dark-matter models of the universe.

Globular Clusters as Extragalactic Distance Indicators: Maximum Likelihood Methods

We have explored the use of maximum likelihood estimation techniques in the use of globular cluster luminosity functions (LFs) as distance indicators. In particular, we have tested size-of-sample effects through the analysis of Monte Carlo simulations of LFs drawn from an assumed universal population like that characterizing the globular clusters in the Local Group. Our working assumption, following others before us, is that the underlying LF is adequately well described by a Gaussian normal in a number vs. absolute magnitude representation.For typically observable sample sizes in studies which are limited to the bright half of the LF, statistical limitations preclude a precise determination of the attributes which fully describe the LF, even in the absence of field object contamination. In particular, the intrinsic dispersion (the shape parameter of the LF) must be taken to be a universal constant, independent of galaxy type; only then may the turnover magnitude (which contains the distance information) be derived with good precision. Some data exist for nearby galaxies (including ellipticals) which permit an assessment of the universality of the intrinsic dispersion: they are not inconsistent with the hypothesis. However, it will be important to test this point in future as more data are secured.Real globular clusters in remote galaxies are unresolved, and the samples are contaminated with foreground field stars and remote background objects. This contamination necessitates corrections which are statistical in nature, applicable to binned LFs. Through numerical simulations, we have tested the limitations imposed by realistic numbers of field objects in globular cluster LFs in remote galaxies, testing for systematic biases and assessing the attainable precision in derived distance as a function of the sample size and the limiting magnitude.

Globular clusters as extragalactic distance indicators - Maximum-likelihood methods

view Abstract Citations (45) References (36) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Globular Clusters as Extragalactic Distance Indicators: Maximum-Liklihood Methods Hanes, David A. ; Whittaker, Donna G. Abstract The authors have explored the use of maximum-likelihood estimation techniques in the use of globular cluster luminosity functions (LFs) as distance indicators. In particular, they have tested size-of-sample effects through the analysis of Monte Carlo simulations of LFs drawn from an assumed universal population like that characterizing the globular clusters in the Local Group. The authors have also considered the effects of the field objects that will contaminate real cluster LFs in remote galaxies and have tested for biases and the attainable precision in derived distances as a function of limiting magnitude (relative to the turnover in the luminosity function). The findings are that maximum-likelihood methods are very robust. Globular clusters are more far-reaching distance indicators than has previously been realized. The authors apply the maximum-likelihood methods to available data and comment upon the implications of the results and the future promise of the method. Publication: The Astronomical Journal Pub Date: October 1987 DOI: 10.1086/114525 Bibcode: 1987AJ.....94..906H Keywords: Astronomical Photometry; Galactic Clusters; Maximum Likelihood Estimates; Computational Astrophysics; Elliptical Galaxies; Monte Carlo Method; Astrophysics; CLUSTERS: GLOBULAR; GALAXIES: GENERAL full text sources ADS | data products SIMBAD (7) NED (7)

A photometric survey of the rich OB association NGC 206 in M31

A detailed UBV photometric survey of the stellar content of the rich OB association NGC 206 has been carried out with two high-quantum-efficiency area detectors. Weighted mean B band magnitudes are derived and used to construct a differential luminosity function, which is in turn transformed to an absolute scale using the estimated total absorption value of 1.15 + or - 0.13 and the geometric distance modulus of 24.07. The B band luminosity function for NGC 206 is transformed to a present day mass function. An initial mass function (IMF) is derived whose power law fit gives a mass-function index value of -2.0 + or - 0.3. This value is consistent with several independent determinations of the slope of the IMF for massive stars. The brightness of the most massive stars in NGC 206 is found to correlate most strongly with the integrated magnitude of the spiral arms and somewhat less with the integrated old-disk luminosity. This indicates that bulge luminosities should be considered in refining the use of the brightest blue stars as extragalactic distance indicators.

Invited Review: Cepheid Variables as Extra-Galactic Distance Indicators

SummaryThe role of cepheid variables in establishing the inner distance scale to nearby galaxies is discussed. Emphasis is placed on the necessity for broad wavelength coverage in attempting to account for metalliclty differences and reddening internal to the parent galaxies. In addition linear detectors are essential in minimizing the effects of any unresolved background contibution to the photometry. Recent infrared observations of Cepheids in Local Group galaxies are surveyed and all published data on extragalactic Cepheids are presented for convenient access.