A colour-excess extinction map of the southern Galactic disc from the VVV and GLIMPSE surveys

Soto, M.; Barbá, R. H.; Minniti, D.; Kunder, Andrea; Majaess, D.; Castellón, José Luis Nilo; Alonso-García, J.; Leone, Giovanni; Morelli, L.; Haikala, L. K.; Firpo, V.; Lucas, P. W.; Emerson, J. P.; Bidin, C. Moni; Geisler, Doug; Saito, R. K.; Gurovich, S.; Ramos, R. Contreras; Rejkuba, M.; Barbieri, M.; Roman-Lopes, Alexandre; Hempel, M.; Alonso, M. V.; Baravalle, L. D.; Borissova, J.; Kurtev, R.; Milla, F.

doi:10.1093/mnras/stz1752

Cited by 13 publications

(12 citation statements)

References 35 publications

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“…Nowadays, a wide range of reddening maps already exist, such as Schlafly & Finkbeiner (2011), Gonzalez et al (2011Gonzalez et al ( , 2018, Minniti et al (2018), Soto et al (2019), Saito et al (2020). We estimate the reddening and the extinction toward this GC following Ruiz-Dern et al (2018) and we benefit from the clear position of the RC in the CMDs.…”

Section: Estimation Of Physical Parameters For Patchick 99mentioning

confidence: 95%

Confirmation and physical characterization of the new bulge globular cluster Patchick 99 from the VVV and Gaia surveys

Garro

Minniti

Gómez

et al. 2021

A&A

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Context. Globular clusters (GCs) are recognised as important tools for understanding the formation and evolution of the Milky Way (MW) because they are the oldest objects in our Galaxy. Unfortunately, the known sample in our MW is still incomplete, especially towards the innermost regions, because of the high differential reddening, extinction, and stellar crowding. Therefore, the discovery of new GC candidates and the confirmation of their true nature are crucial for the census of the MW GC system. Aims. Our main goal is to confirm the physical nature of two GC candidates: Patchick 99 and TBJ 3. Both are located towards the Galactic bulge. We use public data in the near-infrared(IR) passband from the VISTA Variables in the Via Láctea Survey (VVV), the VVV eXtended Survey, and the Two Micron All Sky Survey along with deep optical data from the Gaia Mission DR 2 in order to estimate their main astrophysical parameters, such as reddening and extinction, distance, total luminosity, mean cluster proper motions, size, metallicity, and age. Methods. We investigated both candidates at different wavelengths, allowing us to discard TBJ3 as a possible GC. We use near-IR (Ks vs. (J − Ks)) and optical (G vs. (BP − RP)) colour–magnitude diagrams (CMDs) in order to analyse Patchick 99. First, we decontaminated CMDs, following a statistical procedure, as well as selecting only stars which have similar proper motions (PMs) and are situated within 3′ of the centre. Mean PMs were measured from Gaia DR 2 data. Reddening and extinction were derived by adopting optical and near-IR reddening maps, and were used to estimate the distance modulus and the heliocentric distance. Metallicity and age were evaluated by fitting theoretical stellar isochrones. Results. Reddening and extinction values for Patchick 99 are E(J − Ks) = (0.12 ± 0.02) mag and AKs = (0.09 ± 0.01) mag from the VVV data, whereas we calculate E(BP − RP) = (0.21 ± 0.03) mag and AG = (0.68 ± 0.08) mag from Gaia DR 2 data. We use those values and the magnitude of the RC to estimate the distance, finding good agreement between the near-IR and optical measurements. In fact, we obtain (m − M)0 = (14.02 ± 0.01) mag, equivalent to a distance D = (6.4 ± 0.2) kpc in near-IR and (m − M)0 = (14.23 ± 0.1) mag and so D = (7.0 ± 0.2) kpc in optical. In addition, we derive the metallicity and age for Patchick 99 using our distance and extinction values and fitting PARSEC isochrones. We find [Fe/H]=(−0.2 ± 0.2) dex and t = (10 ± 2) Gyr. The mean PMs for Patchick 99 are μα = ( − 2.98 ± 1.74) mas yr−1 and μδ = ( − 5.49 ± 2.02) mas yr−1 using the Gaia DR 2 data. These are consistent with the bulge kinematics. We also calculate the total luminosity of our cluster and confirm that it is a low-luminosity GC, with MKs = ( − 7.0 ± 0.6) mag. The radius estimation is performed building the radial density profile and we find its angular radius rP99 ∼ 10′. We also recognise seven RR Lyrae star members within 8.2 arcmin from the Patchick 99 centre, but only three of them have PMs matching the mean GC PM, confirming the distance found by other methods. Conclusions. We find that TBJ 3 shows mid-IR emissions that are not present in GCs. We therefore discard TBJ 3 as a GC candidate and focus our work on Patchick 99. We conclude that Patchick 99 is an old metal-rich GC situated in the Galactic bulge. TBJ 3 is a background galaxy.

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Section: Estimation Of Physical Parameters For Patchick 99mentioning

confidence: 95%

Confirmation and physical characterization of the new bulge globular cluster Patchick 99 from the VVV and Gaia surveys

Garro

Minniti

Gómez

et al. 2021

A&A

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“…Then, the extinction and distances are estimated following the same procedures described in our previous works e.g., Garro et al 2021b andMinniti et al 2021b. We adopt existing reddening maps, such as those by Gonzalez et al (2011), Soto et al (2019 and Surot et al (2019) in the NIR and by Schlafly & Finkbeiner (2011) in the optical passbands. Therefore, we use the following relations to derive the color excess and the extinction:…”

Section: Estimation Of Physical Parametersmentioning

confidence: 99%

Unveiling the nature of 12 new low-luminosity Galactic Globular Cluster Candidates

Garro,

Minniti,

Alessi

et al. 2021

Preprint

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Context. The Galactic globular cluster system is incomplete, especially in the low latitude regions of the Galactic bulge and disk. We report the physical characterization of twelve star clusters in the Milky Way, most of which are explored here for the first time. Aims. Our primary aim is determining their main physical parameters, such as reddening and extinction, metallicity, age, total luminosity, mean cluster proper motions (PMs), distances, in order to unveil the physical nature of these clusters. Methods. We study the clusters using optical and near-infrared (NIR) datasets. In particular, we use the Gaia Early Data Release 3 (EDR3) PMs in order to perform a PM-decontamination procedure and build final catalogues with probable-members. We match the Gaia EDR3 with the VISTA Variables in the Vía Láctea extended (VVVX) survey and Two Micron All Sky survey (2MASS) in the NIR, in order to construct complete NIR and optical colour-magnitude diagrams (CMDs) and investigate the clusters properties.Results. The extinctions are evaluated using existing reddening maps. We find ranges spanning 0.09 A K s 0.86 mag and 0.89 A G 4.72 mag in the NIR and optical, respectively. Adopting standard intrinsic red clump (RC) magnitudes and extinction values, we obtain first the distance modulus for each cluster and thereafter their heliocentric distances, that range from about 4 to 20 kpc. Therefore, we are able to place these clusters at 3 R G 14 kpc from the Galactic centre. The best PARSEC isochrone fit yields a metallicity range of −1.8 < [Fe/H] < +0.3 and an approximative age range of 2 < Age < 14 Gyr. Finally, we find that all clusters have low-luminosities, with −6.9 < M V < −3.5 mag. Conclusions. Based on our photometric analysis, we find both open clusters (OCs) and globular clusters (GCs) in our sample. In particular, we confirm the OC nature for Kronberger 100, while we classify Patchick 125 as a metal-poor GC, Ferrero 54 as a metalrich GC, and ESO 92-18 as a possible old OC or young GC. The classification as GC candidates is also suggested for Kronberger 99, Patchick 122, Patchick 126, Riddle 15, FSR 190 and Gaia 2. We also conclude that Kronberger 119 and Kronberger 143 might be either old OCs or young GCs.

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“…Schlegel et al (1998) derived extinction maps from the 100 𝜇m dust emission by DIRBE/IRAS, which were re-calibrated by Schlafly & Finkbeiner (2011). At |b| < 5 • , the presence of contaminating sources was not removed and the reddening reported should be taken with caution (Arce & Goodman 1999;Amôres & Lépine 2005, 2007Gonzalez et al 2012;Soto et al 2013Soto et al , 2019. Nagayama et al (2004) studied the distribution of galaxies at low Galactic latitudes (b ∼ 1.7 • ), and by using a stellar colour-excess technique these authors found a systematic underestimation of A 𝐾 ∼ 0.4 mag in the map of Schlegel et al (1998).…”

Section: Interstellar Extinction and Stellar Densitymentioning

confidence: 99%

The VVV Near-IR Galaxy Catalogue beyond the Galactic disk

Baravalle,

Alonso,

Minniti

et al. 2020

Preprint

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Knowledge about the large-scale distribution of galaxies is far from complete in the Zone of Avoidance, which is mostly due to high interstellar extinction and to source confusion at lower Galactic latitudes. Past near-infrared (NIR) surveys, such as the Two Micron All Sky Survey (2MASS), have shown the power of probing large-scale structure at these latitudes. Our aim is to map the galaxy distribution across the Southern Galactic plane using the VISTA Variables in the Vía Láctea Survey (VVV), which reach 2 to 4 magnitudes deeper than 2MASS. We used SExtractor+PSFEx to identify extended objects and to measure their sizes, the light concentration index, magnitudes, and colours. Morphological and colour constraints and visual inspection were used to confirm galaxies. We present the resulting VVV NIR Galaxy Catalogue of 5563 visually confirmed galaxies, of which only 45 were previously known. This is the largest catalogue of galaxies towards the Galactic plane, with 99% of these galaxies being new discoveries. We found that the galaxy density distribution closely resembled the distribution of low interstellar extinction of the existing NIR maps. We also present a description of the 185 2MASS extended sources observed in the region, of which 16% of these objects had no previous description, which we have now classified. We conclude that interstellar extinction and stellar density are the main limitations for the detection of background galaxies in the Zone of Avoidance. The VVV NIR Galaxy Catalogue is a new data set providing information for extragalactic studies in the Galactic plane.

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A colour-excess extinction map of the southern Galactic disc from the VVV and GLIMPSE surveys

Cited by 13 publications

References 35 publications

Confirmation and physical characterization of the new bulge globular cluster Patchick 99 from the VVV and Gaia surveys

Confirmation and physical characterization of the new bulge globular cluster Patchick 99 from the VVV and Gaia surveys

Unveiling the nature of 12 new low-luminosity Galactic Globular Cluster Candidates

The VVV Near-IR Galaxy Catalogue beyond the Galactic disk

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