scholarly journals The Distance to NGC 5128 (Centaurus A)

2010 ◽  
Vol 27 (4) ◽  
pp. 457-462 ◽  
Author(s):  
Gretchen L. H. Harris ◽  
Marina Rejkuba ◽  
William E. Harris
Keyword(s):  
Surface Brightness ◽  
Luminosity Function ◽  
Current Data ◽  
Long Period ◽  
Surface Brightness Fluctuations ◽  
Period Variable ◽  
Red Giant ◽  
Extragalactic Distance Scale ◽  
Centaurus A

AbstractIn this paper we review the various high precision methods that are now available to determine the distance to NGC 5128. These methods include: Cepheids, TRGB (tip of the red giant branch), PNLF (planetary nebula luminosity function), SBF (surface brightness fluctuations), and Long Period Variable (LPV) Mira stars. From an evaluation of these methods and their uncertainties, we derive a best-estimate distance of 3.8±0.1 Mpc to NGC 5128 and find that this mean is now well supported by the current data. We also discuss the role of NGC 5128 more generally for the extragalactic distance scale as a testbed for the most direct possible comparison among these key methods.

scholarly journals The Planetary Nebulae Luminosity Function (PNLF): current perspectives

2016 ◽  
Vol 12 (S323) ◽  
pp. 298-302 ◽  
Author(s):  
Roberto H. Méndez
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Surface Brightness ◽  
Luminosity Function ◽  
Recent Progress ◽  
Historical Review ◽  
Stellar Populations ◽  
Surface Brightness Fluctuations ◽  
Distance Indicator ◽  
Red Giant

AbstractThis paper starts with a brief historical review about the PNLF and its use as a distance indicator. Then the PNLF distances are compared with Surface Brightness Fluctuations (SBF) distances and Tip of the Red Giant Branch (TRGB) distances. A Monte Carlo method to generate simulated PNLFs is described, leading to the last subject: recent progress in reproducing the expected maximum final mass in old stellar populations, a stellar astrophysics enigma that has been challenging us for quite some time.

scholarly journals The planetary nebula luminosity function

2012 ◽  
Vol 8 (S289) ◽  
pp. 247-254
Author(s):  
Robin Ciardullo
Keyword(s):  
Planetary Nebula ◽  
Surface Brightness ◽  
Luminosity Function ◽  
Zero Point ◽  
Theoretical Explanation ◽  
Number Of Factors ◽  
Surface Brightness Fluctuations ◽  
Type Ia ◽  
Red Giant ◽  
Supernovae Type Ia

AbstractAlthough the method has no theoretical explanation, the [Oiii]λ5007Å planetary nebula luminosity function (PNLF) is an extremely valuable tool for obtaining accurate (< 10%) extragalactic distances out to ~ 18 Mpc. Because the PNLF works in large galaxies of all Hubble types, it is one of the best tools we have for cross-checking the results of other methods and identifying systematic offsets between the Population I and Population II distance ladders. We review the PNLF's calibration and show that the method's Cepheid-derived zero point is virtually identical to that inferred from measurements of the tip of the red giant branch. We then compare the PNLF to the surface brightness fluctuations method and demonstrate that the latter's calibration yields a distance scale that is ~ 15% larger than that of the PNLF. We argue that this offset is likely due to a number of factors, including the effects of reddening on both of the techniques. We conclude by discussing the use of the PNLF for supernovae Type Ia calibration and considering the outstanding problems associated with the method.

scholarly journals Measuring the GC luminosity function up to z ~ 0.2

2009 ◽  
Vol 5 (S266) ◽  
pp. 351-351
Author(s):  
K. A. Alamo-Martínez ◽  
R. A. González-Lópezlira ◽  
J. Blakeslee
Keyword(s):  
Galaxy Formation ◽  
Globular Clusters ◽  
Surface Brightness ◽  
Luminosity Function ◽  
Elliptical Galaxy ◽  
Angular Size ◽  
Spectroscopic Studies ◽  
Stellar Systems ◽  
Surface Brightness Fluctuations ◽  
Specific Frequency

AbstractGlobular clusters (GCs) are stellar systems (~106 M⊙) with very regular symmetry, single age, and single metallicity. Spectroscopic studies have revealed very old ages, suggesting that GCs were formed in the earliest stages of galaxy formation and assembly. The aim of this work is to find out how far we can measure the GC luminosity function, specific frequency, and radial distribution, applying the surface-brightness-fluctuations (SBF) technique to deep ACS images. To this end, we apply the effects caused by higher redshift to HST/ACS images (in two optical bands, F606W and F814W) of M87, an elliptical galaxy with a very well-studied GC system. The effects involved are: (i) evolution, (ii) inverse k correction, (iii) binning of the image to smaller angular size, (iv) cosmological dimming of surface brightness, and (v) noise addition to account for different exposure times. After processing the images we detect the brightest GCs through direct photometry (e.g., with SExtractor), whereas the unresolved clusters are measured through SBFs. The above treatment is repeated for z=0.05, 0.1, 0.14, and 0.18, and the results are compared to the measurements at z=0 to estimate biases and incompleteness.

Evolution and Problems of Red Long Period Variables

1979 ◽  
Vol 46 ◽  
pp. 163-176
Author(s):  
P. R. Wood
Keyword(s):  
Mass Loss ◽  
Atomic Mass ◽  
Surface Enrichment ◽  
Giant Stars ◽  
Long Period ◽  
Wide Range ◽  
Comprehensive Picture ◽  
Period Variable ◽  
Red Giant ◽  
Process Elements

Variability on the red giant branch (RGB) occurs at an interesting and important stage in the life of a star. This phase of evolution is characterized by a substantial amount of mass loss (as a continuous stellar wind or as an abrupt planetary nebula ejection), by flashing of the helium burning shell (at least in stars less massive than ~ 8 M) and by surface enrichment of elements heavier than hydrogen. The galactic importance of these processes is illustrated by the calculations of Cahn and Wyatt (1978) who estimate that material is presently being lost by stars on the RGB at a rate which is roughly equal to the rate at which material is being locked up in stars by star formation. A complementary calculation by Iben and Truran (1978) shows that shell flashing in red giant stars, coupled with mass loss, is a major source of enrichment of the interstellar medium over a wide range of atomic mass from C to heavy s-process elements. Hopefully, studies of the red long period variable (RLPV) stars can assist in the investigation of some of the above processes so that a comprehensive picture of the later phases of stellar evolution can be obtained.

scholarly journals A new measurement of the Hubble constant using Type Ia supernovae calibrated with surface brightness fluctuations

2021 ◽  
Vol 647 ◽  
pp. A72 ◽  
Author(s):  
Nandita Khetan ◽  
Luca Izzo ◽  
Marica Branchesi ◽  
Radosław Wojtak ◽  
Michele Cantiello ◽  
...  
Keyword(s):  
Surface Brightness ◽  
Hubble Constant ◽  
Absolute Magnitude ◽  
Host Galaxy ◽  
Type Ia Supernovae ◽  
Distance Measurements ◽  
Surface Brightness Fluctuations ◽  
Type Ia ◽  
Red Giant ◽  
Ia Supernovae

We present a new calibration of the peak absolute magnitude of Type Ia supernovae (SNe Ia) based on the surface brightness fluctuations (SBF) method, aimed at measuring the value of the Hubble constant. We build a sample of calibrating anchors consisting of 24 SNe hosted in galaxies that have SBF distance measurements. Applying a hierarchical Bayesian approach, we calibrate the SN Ia peak luminosity and extend the Hubble diagram into the Hubble flow by using a sample of 96 SNe Ia in the redshift range 0.02 < z < 0.075, which was extracted from the Combined Pantheon Sample. We estimate a value of H0 = 70.50 ± 2.37 (stat.) ± 3.38 (sys.) km s−1 Mpc−1 (i.e., 3.4% stat., 4.8% sys.), which is in agreement with the value obtained using the tip of the red giant branch calibration. It is also consistent, within errors, with the value obtained from SNe Ia calibrated with Cepheids or the value inferred from the analysis of the cosmic microwave background. We find that the SNe Ia distance moduli calibrated with SBF are on average larger by 0.07 mag than those calibrated with Cepheids. Our results point to possible differences among SNe in different types of galaxies, which could originate from different local environments and/or progenitor properties of SNe Ia. Sampling different host galaxy types, SBF offers a complementary approach to using Cepheids, which is important in addressing possible systematics. As the SBF method has the ability to reach larger distances than Cepheids, the impending entry of the Vera C. Rubin Observatory and JWST into operation will increase the number of SNe Ia hosted in galaxies where SBF distances can be measured, making SBF measurements attractive for improving the calibration of SNe Ia, as well as in the estimation of H0.

scholarly journals Calibration of Surface Brightness Fluctuations for Dwarf Galaxies in the Hyper Suprime-Cam gi Filter System

2021 ◽  
Vol 923 (2) ◽  
pp. 152
Author(s):  
Yoo Jung Kim ◽  
Myung Gyoon Lee
Keyword(s):  
Surface Brightness ◽  
Stellar Population ◽  
Dwarf Galaxies ◽  
Imaging Data ◽  
Standard Candle ◽  
Surface Brightness Fluctuations ◽  
Brightness Fluctuation ◽  
Linear Fit ◽  
Red Giant ◽  
Red Galaxies

Abstract Surface brightness fluctuation (SBF) magnitudes are a powerful standard candle to measure distances to semiresolved galaxies in the local universe, a majority of which are dwarf galaxies that often have bluer colors than bright early-type galaxies. We present an empirical i-band SBF calibration in a blue regime, 0.2 ≲ (g − i)0 ≲ 0.8 in the Hyper Suprime-Cam (HSC) magnitude system. We measure SBF magnitudes for 12 nearby dwarf galaxies of various morphological types with archival HSC imaging data, and use their tip of the red giant branch distances to derive fluctuation–color relations. In order to subtract contributions of fluctuations due to young stellar populations, we use five different g-band magnitude masking thresholds, M g,thres = −3.5, −4.0, −4.5, −5.0, and −5.5 mag. We find that the rms scatter of the linear fit to the relation is the smallest (rms = 0.16 mag) in the case of M g,thres = −4.0 mag, M ¯ i = (−2.65 ± 0.13) + (1.28 ± 0.24) × (g − i)0. This scatter is much smaller than those in the previous studies (rms = 0.26 mag), and is closer to the value for bright red galaxies (rms = 0.12 mag). This calibration is consistent with predictions from metal-poor simple stellar population models.

scholarly journals Long-Period Variables and Planetary Nebulae

1968 ◽  
Vol 34 ◽  
pp. 386-389
Author(s):  
Donald H. Menzel
Keyword(s):  
Magnetic Field ◽  
High Temperature ◽  
Planetary Nebulae ◽  
Symbiotic Stars ◽  
Long Period ◽  
Long Period Variables ◽  
Stellar Photosphere ◽  
Period Variable ◽  
Red Giant ◽  
The Magnetic Field

The occasional appearance of a red giant or long-period variable in planetary nebulae poses a problem for theoretical astrophysics. Such a cool nuclear star would not ordinarily provide a source of ultraviolet radiation necessary for the excitation of the spectrum of a gaseous nebula.One possible solution of this problem postulates the existence of intense magnetic fields in the star. Second, the star itself has a structure resembling that of a miniature, highly compressed planetary, with a high-temperature nuclear star at the centre and a distended atmospheric shell enveloping chiefly the stellar equator.The magnetic field induces a sort of pumping action that creates the tire-shaped envelope from matter ejected near the poles. As this shell grows denser, it radiates like a stellar photosphere at low temperature. Eventually the shell becomes unstable and disperses outward to form and maintain the nebula. A quasi-periodic situation occurs, which explains the variation of light. Ultraviolet light absorbed during the minima, when the shell has vanished, adequately accounts for the nebular excitation. A wide variety of such symbiotic stars occurs, including repeating novae as well as the long-period variables.

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