Conference Theme: Physics and Chemistry of the Late Stages of Stellar EvolutionPost-AGB (PAGB) stars are short-lived, low-intermediate mass objects transitioning from the asymptotic giant branch (AGB) to the white dwarf (WD) phase. These objects are characterised by a constant, core-mass dependent luminosity and a large infrared excess from the dusty envelope ejected at the top of the AGB. PAGB stars provide insights into the evolution of their direct descendants, planetary nebulae (PNe). Calculation of physical characteristics of PAGB are dependent on accurately determined distances scarcely available in the literature. Using the Torun catalogue for PAGB objects, supplemented with archival data, we have determined distances to the known population of Galactic PAGB stars. This is by modelling their spectral energy distributions (SED) with black bodies and numerically integrating over the entire wavelength range to determine the total integrated object flux. For most PAGB stars we assumed their luminosities are based on their positional characteristics and stellar evolution models. RV Tauri stars however are known to follow a period-luminosity relation (PLR) reminiscent of type-2 Cepheids. For these variable PAGB stars we determined their luminosities via the PLR and hence their distances. This allows us to overcome the biggest obstacle to characterising these poorly understood objects that play a vital part in Galactic chemical enrichment.postprin

Bojicic, IS

Frew, DJ

Owers, MS

Parker, QA

Vickers, SB

Journal of Physics Conference Series

Post-AGB (PAGB) stars are short-lived, low-intermediate mass objects transitioning from the asymptotic giant branch (AGB) to the white dwarf (WD) phase. These objects are characterised by a constant, core-mass dependent luminosity and a large infrared excess from the dusty envelope ejected at the top of the AGB. PAGB stars provide insights into the evolution of their direct descendants, planetary nebulae (PNe). Calculation of physical characteristics of PAGB are dependent on accurately determined distances scarcely available in the literature. Using the Torun catalogue for PAGB objects, supplemented with archival data, we have determined distances to the known population of Galactic PAGB stars. This is by modelling their spectral energy distributions (SED) with black bodies and numerically integrating over the entire wavelength range to determine the total integrated object flux. For most PAGB stars we assumed their luminosities are based on their positional characteristics and stellar evolution models. RV Tauri stars however are known to follow a period-luminosity relation (PLR) reminiscent of type-2 Cepheids. For these variable PAGB stars we determined their luminosities via the PLR and hence their distances. This allows us to overcome the biggest obstacle to characterising these poorly understood objects that play a vital part in Galactic chemical enrichment.2 page(s

Vickers, Shane B

Frew, David J

Owers, Matt S

Parker, Quentin A

Bojičič, Ivan S

Macquarie University ResearchOnline

Improving the distances of post-AGB objects in the Milky Way

HKU Scholars Hub

Title Improving the distances of post-AGB objects in the Milky WayAuthor(s) Vickers, SB; Frew, DJ; Owers, MS; Parker, QA; Bojicic, ISCitationThe 11th Pacific Rim Conference on Stellar Astrophysics, HongKong, 14-17 December 2015. In Journal of Physics: ConferenceSeries, 2016, v. 728 n. 7, p. 072013:1-072013:2Issued Date 2016URL http://hdl.handle.net/10722/237688RightsJournal of Physics: Conference Series (Online Edition).Copyright © Institute of Physics Publishing.; This is an author-created, un-copyedited version of an article published in [insertname of journal]. IOP Publishing Ltd is not responsible for anyerrors or omissions in this version of the manuscript or anyversion derived from it. The Version of Record is available onlineat http://dx.doi.org/[insert DOI].; This work is licensed under aCreative Commons Attribution-NonCommercial-NoDerivatives4.0 International License.This content has been downloaded from IOPscience. Please scroll down to see the full text.Download details:IP Address: 147.8.230.84This content was downloaded on 19/01/2017 at 03:38Please note that terms and conditions apply.Improving the distances of post-AGB objects in the Milky WayView the table of contents for this issue, or go to the journal homepage for more2016 J. Phys.: Conf. Ser. 728 072013(http://iopscience.iop.org/1742-6596/728/7/072013)Home Search Collections Journals About Contact us My IOPscienceYou may also be interested in:An ALMA view of the post-AGB object HD 101584H. Olofsson, W. Vlemmings, M. Maercker et al.AGB and Post-AGB Objects. II.Maartje N. SevensterAGB and Post-AGB Objects. I.Maartje N. SevensterOBSERVATIONS OF SiO J = 3--2 AND J = 2--1 EMISSION. II.Se-Hyung Cho, Hyun-Soo Chung, Hyun-Goo Kim et al.MOLECULAR SURVIVAL IN EVOLVED PLANETARY NEBULAEE. D. Tenenbaum, S. N. Milam, N. J. Woolf et al.Collimation of Astrophysical JetsKazimierzJ. Borkowski, JohnM. Blondin and J.Patrick HarringtonObservations of High Rotational CO LinesK. Justtanont, A. G. G.M. Tielens, C.J. Skinner et al.Improving the distances of post-AGB objects in theMilky WayShane B Vickers1, David J Frew2, Matt S Owers1,3, QuentinA Parker2,3, and Ivan S Bojicˇicˇ21Department of Physics and Astronomy, Macquarie University, NSW 2109, Australia2Department of Physics, The University of Hong Kong, Pokfulam Road, Hong Kong, China3Australian Astronomical Observatory, PO Box 915, North Ryde, NSW 1670, AustraliaE-mail: 1 shane.vickers@students.mq.edu.auAbstract.Post-AGB (PAGB) stars are short-lived, low-intermediate mass objects transitioning fromthe asymptotic giant branch (AGB) to the white dwarf (WD) phase. These objects arecharacterised by a constant, core-mass dependent luminosity and a large infrared excess fromthe dusty envelope ejected at the top of the AGB. PAGB stars provide insights into the evolutionof their direct descendants, planetary nebulae (PNe). Calculation of physical characteristics ofPAGB are dependent on accurately determined distances scarcely available in the literature.Using the Torun catalogue for PAGB objects, supplemented with archival data, we havedetermined distances to the known population of Galactic PAGB stars. This is by modellingtheir spectral energy distributions (SED) with black bodies and numerically integrating overthe entire wavelength range to determine the total integrated object flux. For most PAGBstars we assumed their luminosities are based on their positional characteristics and stellarevolution models. RV Tauri stars however are known to follow a period-luminosity relation(PLR) reminiscent of type-2 Cepheids. For these variable PAGB stars we determined theirluminosities via the PLR and hence their distances. This allows us to overcome the biggestobstacle to characterising these poorly understood objects that play a vital part in Galacticchemical enrichment.1. IntroductionPre-planetary nebulae (PPNe) are a very brief phase in the late-stage evolution of mid-massstars (∼1 – 8M) between the asymptotic giant branch (AGB) and the PN phase. The tenuousenvelope ejection in the final superwind of AGB evolution reaches rates of 10−4 M yr−1, andincreases the effective temperature of the central star. The rate of increase is a strong function ofcore mass [1,2]. RV Tauri stars are F to K type variable stars with alternating deep and shallowminima and are believed to be luminous population II Cepheids that follow a period-luminosityrelationship similar to type-2 Cepheids [3]. Understanding these objects depends on accuratedistances that are not yet available for the more poorly-quantified objects. We aim to rectifythis by determining accurate distances to the known Galactic PAGB star population [6].2. SampleWe use the Torun´ catalogue of PAGB and related objects [4,5] and flux data for known Galacticobjects that includes 209 likely PPN, 112 RV Tauri, 72 R CrB/eHe/LTP and 87 possible PAGB11th Pacific Rim Conference on Stellar Astrophysics IOP PublishingJournal of Physics: Conference Series 728 (2016) 072013 doi:10.1088/1742-6596/728/7/072013Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distributionof this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.Published under licence by IOP Publishing Ltd 1 Log PFigure 1. I-Band PLR for LMC and SMC RV Tauri variables taken from [7,8].objects. We determine RV Tauri star distances via a newly defined period luminosity relation.These data are supplemented with publicly available data from other surveys from the opticalto the sub-mm to build SEDs for all objects.3. MethodWe use the SED fitting method described in [6], with the luminosity calculation for RV Tauristars described as follows. Using the data from [4,5] as well as publicly available photometry, webuild an SED that is fit with a number of black body functions to calculate the total bolometricflux. This is used with the luminosity to determine the distance. Light curves and photometryfrom [7,8] are used to define a new period-luminosity relation for RV Tauri stars in both theLMC and the SMC to determine luminosities for their Galactic counterparts. Using these datawe have defined a new period luminosity relations for RV Tauri stars in multiple wavebands theI-band PLR is shown in Figure 1.4. Summary and future workWith a new catalogue of distances to the different PAGB objects we can work on determiningthe progenitors, amongst other physical parameters, for the different classes. With distances wecan compare the z-heights for the different object classes, shining light on their progenitors. Thiswill help uncover the shaping mechanisms responsible for the observed complex morphologies.This is the first ever distance catalogue for these objects.References[1] Scho¨nberner D 1983 Astrophys. J. 272 708[2] Vassiliadis E and Wood P R 1994 Astrophys. J. Suppl. Series 92 125[3] Alcock et al 1998 Astron. J. 115 1921[4] Szczerba R, Sio´dmiak N, Stasin´ska G and Borkowski J 2007 Astron. Astrophys. 469 799[5] Szczerba R, Sio´dmiak N, Stasin´ska G, Borkowski J, Garc´ıa-Lario P, Sua´rez O, Hajduk M and Garc´ıa-Herna´ndezD A 2012 Proc. Int. Astron. Union (S283) 7 506[6] Vickers S B, Frew D J, Parker Q A and Bojicˇicˇ I S 2015 Mon. Not. R. Astron. Soc. 447 1673[7] Matsunaga N et al 2006 Mon. Not. R. Astron. Soc. 370 1979[8] Ripepi V et al 2015 Mon. Not. R. Astron. Soc. 446 3034[9] Vickers S B, Frew D J, Owers M S, Parker Q A and Bojicˇicˇ I S 2016 Mon. Not. R. Astron. Soc. in preparation11th Pacific Rim Conference on Stellar Astrophysics IOP PublishingJournal of Physics: Conference Series 728 (2016) 072013 doi:10.1088/1742-6596/728/7/0720132

Shane B Vickers

David J Frew

Matt S Owers

Quentin A Parker

Ivan S Bojičič

Crossref

Post-AGB (PAGB) stars are short-lived, low-intermediate mass objects transitioning from the asymptotic giant branch (AGB) to the white dwarf (WD) phase. These objects are characterised by a constant, core-mass dependent luminosity and a large infrared excess from the dusty envelope ejected at the top of the AGB. PAGB stars provide insights into the evolution of their direct descendants, planetary nebulae (PNe). Calculation of physical characteristics of PAGB are dependent on accurately determined distances scarcely available in the literature. Using the Torun catalogue for PAGB objects, supplemented with archival data, we have determined distances to the known population of Galactic PAGB stars. This is by modelling their spectral energy distributions (SED) with black bodies and numerically integrating over the entire wavelength range to determine the total integrated object flux. For most PAGB stars we assumed their luminosities are based on their positional characteristics and stellar evolution models. RV Tauri stars however are known to follow a period-luminosity relation (PLR) reminiscent of type-2 Cepheids. For these variable PAGB stars we determined their luminosities via the PLR and hence their distances. This allows us to overcome the biggest obstacle to characterising these poorly understood objects that play a vital part in Galactic chemical enrichment

Vickers, Shane B.

Frew, David J.

Owers, Matt S.

Parker, Quentin A.

Bojicic, Ivan S. (R16652)

Western Sydney ResearchDirect

Journal of Physics: Conference SeriesPAPER • OPEN ACCESSImproving the distances of post-AGB objects in theMilky WayTo cite this article: Shane B Vickers et al 2016 J. Phys.: Conf. Ser. 728 072013 View the article online for updates and enhancements.You may also likeBD+14°3061: A Luminous Yellow Post-AGB Star in the Galactic HaloHoward E. Bond-Astrometric Membership Tests for theZinn–Newell–Gibson UV-bright Stars inGalactic Globular ClustersHoward E. Bond-OBSERVED RELATIONSHIP BETWEENCO 2–1 AND DUST EMISSION DURINGTHE POST-ASYMPTOTIC-GIANT-BRANCH PHASEJ. H. He, R. Szczerba, T. I. Hasegawa etal.-This content was downloaded from IP address 137.154.212.76 on 30/09/2022 at 05:31Improving the distances of post-AGB objects in theMilky WayShane B Vickers1, David J Frew2, Matt S Owers1,3, QuentinA Parker2,3, and Ivan S Bojičič21Department of Physics and Astronomy, Macquarie University, NSW 2109, Australia2Department of Physics, The University of Hong Kong, Pokfulam Road, Hong Kong, China3Australian Astronomical Observatory, PO Box 915, North Ryde, NSW 1670, AustraliaE-mail: 1 shane.vickers@students.mq.edu.auAbstract.Post-AGB (PAGB) stars are short-lived, low-intermediate mass objects transitioning fromthe asymptotic giant branch (AGB) to the white dwarf (WD) phase. These objects arecharacterised by a constant, core-mass dependent luminosity and a large infrared excess fromthe dusty envelope ejected at the top of the AGB. PAGB stars provide insights into the evolutionof their direct descendants, planetary nebulae (PNe). Calculation of physical characteristics ofPAGB are dependent on accurately determined distances scarcely available in the literature.Using the Torun catalogue for PAGB objects, supplemented with archival data, we havedetermined distances to the known population of Galactic PAGB stars. This is by modellingtheir spectral energy distributions (SED) with black bodies and numerically integrating overthe entire wavelength range to determine the total integrated object flux. For most PAGBstars we assumed their luminosities are based on their positional characteristics and stellarevolution models. RV Tauri stars however are known to follow a period-luminosity relation(PLR) reminiscent of type-2 Cepheids. For these variable PAGB stars we determined theirluminosities via the PLR and hence their distances. This allows us to overcome the biggestobstacle to characterising these poorly understood objects that play a vital part in Galacticchemical enrichment.1. IntroductionPre-planetary nebulae (PPNe) are a very brief phase in the late-stage evolution of mid-massstars (∼1 – 8 M) between the asymptotic giant branch (AGB) and the PN phase. The tenuousenvelope ejection in the final superwind of AGB evolution reaches rates of 10−4 M yr−1, andincreases the effective temperature of the central star. The rate of increase is a strong function ofcore mass [1,2]. RV Tauri stars are F to K type variable stars with alternating deep and shallowminima and are believed to be luminous population II Cepheids that follow a period-luminosityrelationship similar to type-2 Cepheids [3]. Understanding these objects depends on accuratedistances that are not yet available for the more poorly-quantified objects. We aim to rectifythis by determining accurate distances to the known Galactic PAGB star population [6].2. SampleWe use the Toruń catalogue of PAGB and related objects [4,5] and flux data for known Galacticobjects that includes 209 likely PPN, 112 RV Tauri, 72 R CrB/eHe/LTP and 87 possible PAGB11th Pacific Rim Conference on Stellar Astrophysics IOP PublishingJournal of Physics: Conference Series 728 (2016) 072013 doi:10.1088/1742-6596/728/7/072013Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distributionof this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.Published under licence by IOP Publishing Ltd 1 Log PFigure 1. I-Band PLR for LMC and SMC RV Tauri variables taken from [7,8].objects. We determine RV Tauri star distances via a newly defined period luminosity relation.These data are supplemented with publicly available data from other surveys from the opticalto the sub-mm to build SEDs for all objects.3. MethodWe use the SED fitting method described in [6], with the luminosity calculation for RV Tauristars described as follows. Using the data from [4,5] as well as publicly available photometry, webuild an SED that is fit with a number of black body functions to calculate the total bolometricflux. This is used with the luminosity to determine the distance. Light curves and photometryfrom [7,8] are used to define a new period-luminosity relation for RV Tauri stars in both theLMC and the SMC to determine luminosities for their Galactic counterparts. Using these datawe have defined a new period luminosity relations for RV Tauri stars in multiple wavebands theI-band PLR is shown in Figure 1.4. Summary and future workWith a new catalogue of distances to the different PAGB objects we can work on determiningthe progenitors, amongst other physical parameters, for the different classes. With distances wecan compare the z-heights for the different object classes, shining light on their progenitors. Thiswill help uncover the shaping mechanisms responsible for the observed complex morphologies.This is the first ever distance catalogue for these objects.References[1] Schönberner D 1983 Astrophys. J. 272 708[2] Vassiliadis E and Wood P R 1994 Astrophys. J. Suppl. Series 92 125[3] Alcock et al 1998 Astron. J. 115 1921[4] Szczerba R, Siódmiak N, Stasińska G and Borkowski J 2007 Astron. Astrophys. 469 799[5] Szczerba R, Siódmiak N, Stasińska G, Borkowski J, Garćıa-Lario P, Suárez O, Hajduk M and Garćıa-HernándezD A 2012 Proc. Int. Astron. Union (S283) 7 506[6] Vickers S B, Frew D J, Parker Q A and Bojičič I S 2015 Mon. Not. R. Astron. Soc. 447 1673[7] Matsunaga N et al 2006 Mon. Not. R. Astron. Soc. 370 1979[8] Ripepi V et al 2015 Mon. Not. R. Astron. Soc. 446 3034[9] Vickers S B, Frew D J, Owers M S, Parker Q A and Bojičič I S 2016 Mon. Not. R. Astron. Soc. in preparation11th Pacific Rim Conference on Stellar Astrophysics IOP PublishingJournal of Physics: Conference Series 728 (2016) 072013 doi:10.1088/1742-6596/728/7/0720132

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Improving the distances of post-AGB objects in the Milky Way

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