Unveiling short-period binaries in the inner VVV bulge

Botan, E.; Saito, R. K.; Minniti, D.; Kanaan, A.; Ramos, R. Contreras; Ferreira, T. S.; Gramajo, L. V.; Navarro, María Gabriela

doi:10.1093/mnras/stab888

Cited by 10 publications

(5 citation statements)

References 47 publications

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“…In passing, we note that the inclusion of RRc variables is crucial to investigate the topology of the instability strip and to address several open problems concerning field and cluster RRLs. However, their inclusion brings forward the thorny problem of short period eclipsing binaries mimicking the luminosity variation typical of RRc variables (Botan et al 2021). To overcome the contamination of eclipsing binaries we devised a new method based on the optical (Gaia, Clementini et al 2019) and mid-infrared (MIR from NEOWISE, Mainzer et al 2011) amplitude ratios.…”

Section: The Rrl Spectroscopic Catalogmentioning

confidence: 99%

On the Use of Field RR Lyrae as Galactic Probes. I. The Oosterhoff Dichotomy Based on Fundamental Variables*

Fabrizio

Bono

Braga

et al. 2019

ApJ

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We collected a large data set of field RR Lyrae stars (RRLs) by using catalogues already available in the literature and Gaia DR2. We estimated the iron abundances for a sub-sample of 2,382 fundamental RRLs (∆S method: Ca II K, Hβ, Hγ and Hδ lines) for which are publicly available medium-resolution SDSS-SEGUE spectra. We also included similar estimates available in the literature ending up with the largest and most homogeneous spectroscopic data set ever collected for RRLs (2,903). The metallicity scale was validated by using iron abundances based on high resolution spectra for a fundamental field RRL (V Ind), for which we collected X-shooter spectra covering the entire pulsation cycle. The peak ([Fe/H]=-1.59±0.01) and the standard deviation (σ=0.43 dex) of the metallicity distribution agree quite well with similar estimates available in the literature. The current measurements disclose a well defined metal-rich tail approaching Solar iron abundance. The spectroscopic sample plotted in the Bailey diagram (period vs luminosity amplitude) shows a steady variation when moving from the metal-poor ([Fe/H]=-3.0/-2.5) to the metal-rich ([Fe/H]=-0.5/0.0) regime. The smooth transition in the peak of the period distribution as a function of the metallicity strongly indicates that the longstanding problem of the Oosterhoff dichotomy among Galactic globulars is the consequence of the lack of metal-intermediate clusters hosting RRLs. We also found that the luminosity amplitude, in contrast Corresponding author: Michele Fabrizio michele.fabrizio@ssdc.asi.it * Partially based on observations collected under ESO programmes 297.D-5047 (PI. G. Bono) and 083.B-0281 (PI. D. Romano). arXiv:1908.02064v2 [astro-ph.SR] 7 Aug 2019 M. Fabrizio et al.with period, does not show a solid correlation with metallicity. This suggests that period-amplitudemetallicity relations should be cautiously treated.

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Section: The Rrl Spectroscopic Catalogmentioning

confidence: 99%

On the Use of Field RR Lyrae as Galactic Probes. I. The Oosterhoff Dichotomy Based on Fundamental Variables*

Fabrizio

Bono

Braga

et al. 2019

ApJ

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“…the VIVACE catalogu (Molnar et al 2021), and previous works on individual Galactic regions (e.g. Molina et al 2019;Medina et al 2021;Alonso-García et al 2021), searches for short-timescale pulsating sources (Bhardwaj et al 2017;Minniti et al 2017) and eclipsing binaries (Botan et al 2021). Contreras Peña et al (2017a, hereafter Paper I) identified 816 variables (Δ𝐾 𝑠 > 1 mag) from the first 4.5 years of the VVV data for the Galactic mid-plane region, including 247 long-term periodic variables (𝑃 > 100 d), among them 65 YSO candidates.…”

Section: Introductionmentioning

confidence: 99%

Large-amplitude periodic outbursts and long-period variables in the VVV VIRAC2-β data base

Guo

Lucas

Smith

et al. 2022

Monthly Notices of the Royal Astronomical Society

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The VISTA Variables in the Via Lactea (VVV) survey obtained near-infrared photometry toward the Galactic bulge and the southern disc plane for a decade (2010 – 2019). We designed a modified Lomb-Scargle method to search for large-amplitude ($\Delta K_{s, 2{{\ \rm per\ cent}}-98{{\ \rm per\ cent}}}$ > 1.5 mag) mid to long-term periodic variables (P>10 d) in the 2nd version of VVV Infrared Astrometric Catalogue (VIRAC2-β). In total, 1520 periodic sources were discovered, including 59 candidate periodic outbursting young stellar objects (YSOs), based on the unique morphology of the phase-folded light curves, proximity to Galactic H ii regions and mid-infrared colours. Five sources are spectroscopically confirmed as accreting YSOs. Both fast-rise/slow-decay and slow-rise/fast-decay periodic outbursts were found, but fast-rise/slow-decay outbursts predominate at the highest amplitudes. The multi-wavelength colour variations are consistent with a variable mass accretion process, as opposed to variable extinction. The cycles are likely to be caused by dynamical perturbations from stellar or planetary companions within the circumstellar disc. An additional search for periodic variability amongst YSO candidates in published Spitzer-based catalogues yielded a further 71 candidate periodic accretors, mostly with lower amplitudes. These resemble cases of pulsed accretion but with unusually long periods and greater regularity. The majority of other long-period variables are pulsating dusty Miras with smooth and symmetric light curves. We find that some Miras have redder W3 − W4 colours than previously thought, most likely due to their surface chemical compositions.

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“…Prior to these surveys, a time-domain survey with high cadence using PRIME will play an important role in providing new insights into the formation history and structure of our galaxy. In addition to aspects of microlensing, the time-domain data by the PRIME microlensing survey will provide useful information in studies of the Galactic structure, through variable stars such as eclipsing binaries, pulsating RR Lyrae, and Cepheids (e.g., Pietrukowicz et al 2020;Botan et al 2021).…”

Section: Inner Galactic Bulge Survey By Primementioning

confidence: 99%

Prediction of Planet Yields by the PRime-focus Infrared Microlensing Experiment Microlensing Survey

Kondo

Sumi

Koshimoto

et al. 2023

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The PRime-focus Infrared Microlensing Experiment (PRIME) will be the first to conduct a dedicated near-infrared microlensing survey by using a 1.8 m telescope with a wide field of view of 1.45 deg2 at the South African Astronomical Observatory. The major goals of the PRIME microlensing survey are to measure the microlensing event rate in the inner Galactic bulge to help design the observing strategy for the exoplanet microlensing survey by the Nancy Grace Roman Space Telescope and to make a first statistical measurement of exoplanet demographics in the central bulge fields where optical observations are very difficult owing to the high extinction in these fields. Here we conduct a simulation of the PRIME microlensing survey to estimate its planet yields and determine the optimal survey strategy, using a Galactic model optimized for the inner Galactic bulge. In order to maximize the number of planet detections and the range of planet mass, we compare the planet yields among four observation strategies. Assuming the Cassan et al. mass function as modified by Penny et al., we predict that PRIME will detect planetary signals for 42–52 planets (1–2 planets with M p ≤ 1M ⊕, 22−25 planets with mass 1M ⊕ < M p ≤ 100M ⊕, 19–25 planets 100M ⊕ < M p ≤ 10, 000M ⊕), per year depending on the chosen observation strategy.

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Unveiling short-period binaries in the inner VVV bulge

Cited by 10 publications

References 47 publications

On the Use of Field RR Lyrae as Galactic Probes. I. The Oosterhoff Dichotomy Based on Fundamental Variables*

On the Use of Field RR Lyrae as Galactic Probes. I. The Oosterhoff Dichotomy Based on Fundamental Variables*

Large-amplitude periodic outbursts and long-period variables in the VVV VIRAC2-β data base

Prediction of Planet Yields by the PRime-focus Infrared Microlensing Experiment Microlensing Survey

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