Evolutionary and pulsation properties of Type II Cepheids

Bono, G.; Braga, V. F.; Fiorentino, G.; Salaris, Maurizio; Pietrinferni, A.; Castellani, M.; Criscienzo, M. Di; Fabrizio, M.; Martı́nez-Vázquez, C. E.; Monelli, M.

doi:10.1051/0004-6361/202038191

Cited by 21 publications

(16 citation statements)

References 122 publications

(140 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…3. Theoretical models (e.g., Bono et al 2020) show that at Z = 0.001 HB stars with masses smaller than ∼0.56 M e skip the thermal pulse AGB stage, where the third dredge-up occurs. This is because their envelope mass is so small that the alternate helium and hydrogen burning in shells surrounding the carbon-oxygen core cannot occur.…”

Section: Discussionmentioning

confidence: 99%

“…This expectation is also consistent with the conclusion by Cassisi et al (2014) that the mass distribution along the HB in the two clusters is essentially the same, with the large majority of HB stars having masses smaller than ∼0.56 M e . According to theoretical models (BaSTI and Bono et al 2020), at the considered metallicity (Z = 0.001), these stars do not experience the thermal pulse AGB stage during which the third dredge-up occurs. We can thus assume that, as in M13, approximately 70% of the WD progenitors in NGC 6752 end their evolution with hydrogen envelopes thick enough (a few 10 −4 M e ) to guarantee stable hydrogen burning during the subsequent WD cooling stage.…”

Section: Comparing the Wd Lf Of Ngc 6752 And M13mentioning

confidence: 93%

See 1 more Smart Citation

Slowly Cooling White Dwarfs in NGC 6752

Chen¹,

Ferraro²,

Cadelano³

et al. 2022

ApJ

Self Cite

View full text Add to dashboard Cite

Recently, a new class of white dwarfs (“slowly cooling WDs”) has been identified in the globular cluster M13. The cooling time of these stars is increased by stable thermonuclear hydrogen burning in their residual envelope. These WDs are thought to be originated by horizontal branch (HB) stars populating the HB blue tail that skipped the asymptotic giant branch phase. To further explore this phenomenon, we took advantage of deep photometric data acquired with the Hubble Space Telescope in the near-ultraviolet and investigate the bright portion of the WD cooling sequence in NGC 6752, another Galactic globular cluster with a metallicity, age, and HB morphology similar to M13. The normalized WD luminosity function derived in NGC 6752 turns out to be impressively similar to that observed in M13, in agreement with the fact that the stellar mass distribution along the HB of these two systems is almost identical. As in the case of M13, the comparison with theoretical predictions is consistent with ∼70% of the investigated WDs evolving at slower rates than standard, purely cooling WDs. Thanks to its relatively short distance from Earth, NGC 6752 photometry reaches a luminosity 1 order of a magnitude fainter than the case of M13, allowing us to sample a regime where the cooling time delay, with respect to standard WD models, reaches ∼300 Myr. The results presented in this paper provide new evidence for the existence of slowly cooling WDs and further support to the scenario proposing a direct causal connection between this phenomenon and the HB morphology of the host stellar cluster.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Comparing the Wd Lf Of Ngc 6752 And M13mentioning

confidence: 93%

Slowly Cooling White Dwarfs in NGC 6752

Chen¹,

Ferraro²,

Cadelano³

et al. 2022

ApJ

Self Cite

View full text Add to dashboard Cite

show abstract

“…To convert the σ into the uncertainty on V γ , one has simply to factor in Amp(RV). Since the typical Amp(RV) for RRc variables in H γ and H δ range between 10 and 30 km/s (Bono et al 2020b), the largest possible uncertainty introduced by the RVC template is of ∼4 km/s. However, the largest absolute uncertainties are associated with the H α and H β RVC templates for RRab1 period bin (σ ∼0.05).…”

Section: Analytical Fits Of the Rvc Templatesmentioning

confidence: 99%

On the Use of Field RR Lyrae as Galactic Probes. V. Optical and radial velocity curve templates

Braga,

Crestani,

Fabrizio

et al. 2021

Preprint

Self Cite

View full text Add to dashboard Cite

We collected the largest spectroscopic catalog of RR Lyrae (RRLs) including ≈20,000 high-, medium-and low-resolution spectra for ≈10,000 RRLs. We provide the analytical forms of radial velocity curve (RVC) templates. These were built using 36 RRLs (31 fundamental-split into three period bins-and 5 first overtone pulsators) with well-sampled RVCs based on three groups of metallic lines (Fe, Mg, Na) and four Balmer lines (H α , H β , H γ , H δ ). We tackled the long-standing problem of the reference epoch to anchor light curve and RVC templates. For the V-band, we found that the residuals of the templates anchored to the phase of the mean magnitude along the rising branch are ∼35% to ∼45% smaller than those anchored to the phase of maximum light. For the RVC, we used two independent reference epochs for metallic and Balmer lines and we verified that the residuals of the RVC templates anchored to the phase of mean RV are from 30% (metallic lines) up to 45% (Balmer lines) smaller than those anchored to the phase of minimum RV. We validated our RVC templates by using both the single-and the three-phase points approach. We found that barycentric velocities based on our RVC templates are two-three times more accurate than those available in the literature. We applied the current RVC templates to Balmer lines RVs of RRLs in the globular NGC 3201 collected with MUSE at VLT. We found the cluster barycentric RV of V γ =496.89±8.37(error)±3.43 (standard deviation) km/s, which agrees well with literature estimates.

show abstract

“…Several studies have been conducted to investigate the pulsation and evolutionary status of T2Cs as described in reviews by Wallerstein (2002) and Neilson et al (2016). A number of theoretical evolutionary track grids and pulsation models have been developed (see e.g., Gingold 1976;Bono et al 1997aBono et al ,b, 2016Bono et al , 2020Smolec 2016;Dotter 2008;Dell'Omodarme et al 2012) that can be used to compute the pulsation properties including period changes, period distributions, crossing modes and other characteristics of T2Cs in their post-HB evolution. Gingold 1976;Bono et al 2016;Sandage et al 1994;Wallerstein 2002).…”

Section: Introductionmentioning

confidence: 99%

“…However, Gonzales (1994) discovered one example that demonstrated blue-ward advancement with a decreasing period. Furthermore, the current theoretical framework (Bono et al 2020) predicts that BLH stars can experience both negative and positive period changes during their post-HB evolution. This prediction was based on gravo-nuclear instabilities at the onset of Heshell burning, following the exhaustion of helium in the core.…”

Section: Introductionmentioning

confidence: 99%

A search for period changes of eight short-period Type II Cepheids

Yacob

Бердников

Pastukhova

et al. 2022

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

In this study, we investigate the period changes of eight short-period Type II Cepheids of the BL Her subtype, i.e., with periods in the 1-4 day range. The O − C diagrams for these stars are constructed using all suitable observational data from ground and space surveys. This spans a time interval of over one century and includes digitized photographic plates as well as photometry from the literature. The O − C diagrams show parabolic evolutionary trends, which indicate the presence of both increasing and decreasing periods for these eight short period stars. These period changes are in good agreement with the recent theoretical evolutionary framework and stellar evolution models for BL Her stars. The pulsation stability test proposed by Lombard and Koen also suggests that the changes in the periods are real.

show abstract

Evolutionary and pulsation properties of Type II Cepheids

Abstract: The version presented here may differ from the published version or from the version of the record. Please see the repository URL above for details on accessing the published version and note that access may require a subscription.

Cited by 21 publications

References 122 publications

Slowly Cooling White Dwarfs in NGC 6752

Slowly Cooling White Dwarfs in NGC 6752

On the Use of Field RR Lyrae as Galactic Probes. V. Optical and radial velocity curve templates

A search for period changes of eight short-period Type II Cepheids

Contact Info

Product

Resources

About