J/A+A/695/A104 Hα-excess S-PLUS Catalogs (Gutierrez-Soto+, 2025)
Mapping Hα-excess candidate point sources in the southern hemisphere
using S-PLUS data.
Gutierrez-Soto L.A., Lopes de Oliveira R., Akras S., Goncalves D.R.,
Lomeli-Nunez L.F., Mendes de Oliveira C., Telles E., Alvarez-Candal A.,
Borges Fernandes M., Daflon S., Ferreira Lopes C.E., Grossi M., Hazarika D.,
Humire P.K., Lima-Dias C., Lopes A.R., Nilo Castellon J.L., Panda S.,
Kanaan A., Ribeiro T., Schoenell W.
<Astron. Astrophys. 695, A104 (2025)>
=2025A&A...695A.104G 2025A&A...695A.104G (SIMBAD/NED BibCode)
ADC_Keywords: Surveys ; Novae ; Binaries, cataclysmic ; QSOs ; Stars, emission ;
Photometry ; Optical
Keywords: techniques: photometric - surveys - novae, cataclysmic variables -
quasars: emission lines
Abstract:
We use the Southern Photometric Local Universe Survey (S-PLUS) Fourth
Data Release (DR4) to identify and classify Hα-excess point
source candidates in the Southern Sky. This approach combines
photometric data from 12 S-PLUS filters with machine learning
techniques to improve source classification and advance our
understanding of Hα-related phenomena.
Our goal is to enhance the classification of Hα-excess point
sources by distinguishing between Galactic and extragalactic objects,
particularly those with redshifted emission lines, and to identify
sources where the Hα excess is associated with variability
phenomena, such as short-period RR Lyrae stars.
We selected Hα-excess candidates using the (r-J0660) versus
(r-i) colour-colour diagram from the S-PLUS main survey (MS) and
Galactic Disk Survey (GDS). Dimensionality reduction was achieved
using UMAP, followed by HDBSCAN clustering. We refined this by
incorporating infrared data, improving the separation of source types.
A Random Forest model was then trained on the clustering results to
identify key colour features for the classification of Hα-excess
sources. New, effective colour-colour diagrams were constructed by
combining data from S-PLUS MS and infrared data. These diagrams,
alongside tentative colour criteria, offer a preliminary
classification of Hα-excess sources without the need for complex
algorithms.
Combining multiwavelength photometric data with machine learning
techniques significantly improved the classification of
Hα-excess sources. We identified 6956 sources with excess in the
J0660 filter, and cross-matching with SIMBAD allowed us to explore the
types of objects present in our catalog, including emission-line
stars, young stellar objects, nebulae, stellar binaries, cataclysmic
variables, variable stars, and extragalactic sources such as QSOs,
AGNs, and galaxies. The cross-match also revealed X-ray sources,
transients, and other peculiar objects. Using S-PLUS colours and
machine learning, we successfully separated RR Lyrae stars from both
other Galactic stars and extragalactic objects. Additionally, we
achieved a clear separation between Galactic and extragalactic
sources. However, distinguishing cataclysmic variables from QSOs at
specific redshifts remained challenging. Incorporating infrared data
refined the classification, enabling us to separate Galactic from
extragalactic sources and to distinguish cataclysmic variables from
QSOs. The Random Forest model, trained on HDBSCAN results, highlighted
key colour features that distinguish the different classes of
Hα-excess sources, providing a robust framework for future
studies such as follow-up spectroscopy.
Description:
This catalog presents 6956 Hα-excess candidates from S-PLUS DR4,
identified via the (r-J0660) versus (r-i) colour-colour diagram.
Sources were selected from two DR4 subsurveys: the Main Survey (MS)
using 3-arcsec aperture-corrected (PStotal) photometry, and the
Galactic Disk Survey (GDS) using PSF photometry. MS Hα sources
were classified into different classes via UMAP dimensionality
reduction and HDBSCAN clustering: first using S-PLUS photometry alone,
then augmented with WISE infrared data.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
hasms.dat 485 3637 Main survey Hα-excess sources with UMAP/WISE
hasgds.dat 343 3319 Galactic Disk Survey Hα-excess sources
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See also:
II/380 : S-PLUS DR4 photometrical catalog (Herpich+, 2024)
Byte-by-byte Description of file: hasms.dat
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Bytes Format Units Label Explanations
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1- 28 A28 --- ID Unique source identifier, iDR43*
30- 41 F12.8 deg RAdeg Right Ascension (J2000)
43- 54 F12.8 deg DEdeg Declination (J2000)
56- 66 F11.8 mag umag S-PLUS u-band PStotal magnitude
68- 81 F14.8 mag e_umag Error in u-band magnitude
83- 93 F11.8 mag J0378mag S-PLUS J0378 PStotal magnitude
95-108 F14.8 mag e_J0378mag Error in J0378mag
110-120 F11.8 mag J0395mag S-PLUS J0395 PStotal magnitude
122-135 F14.8 mag e_J0395mag Error in J0395mag
137-147 F11.8 mag J0410mag S-PLUS J0410 PStotal magnitude
149-162 F14.8 mag e_J0410mag Error in J0410mag
164-174 F11.8 mag J0430mag S-PLUS J0430 PStotal magnitude
176-189 F14.8 mag e_J0430mag Error in J0430mag
191-201 F11.8 mag gmag S-PLUS g-band PStotal magnitude
203-212 F10.8 mag e_gmag Error in gmag
214-224 F11.8 mag J0515mag S-PLUS J0515 PStotal magnitude
226-239 F14.8 mag e_J0515mag Error in J0515mag
241-251 F11.8 mag rmag S-PLUS r-band PStotal magnitude
253-262 F10.8 mag e_rmag Error in rmag
264-274 F11.8 mag J0660mag S-PLUS J0660 PStotal magnitude
276-285 F10.8 mag e_J0660mag Error in J0660mag
287-297 F11.8 mag imag S-PLUS i-band PStotal magnitude
299-308 F10.8 mag e_imag Error in imag
310-320 F11.8 mag J0861mag S-PLUS J0861 PStotal magnitude
322-335 F14.8 mag e_J0861mag Error in J0861mag
337-347 F11.8 mag zmag S-PLUS z-band PStotal magnitude
349-359 F11.8 mag e_zmag Error in zmag
361-373 A13 --- SimbadType SIMBAD classification (1)
375-386 F12.8 mag W1mag ?=-99 AllWISE W1 magnitude
388-399 F12.8 mag e_W1mag ?=-99 Error in W1mag
401-412 F12.8 mag W2mag ?=-99 AllWISE W2 magnitude
414-425 F12.8 mag e_W2mag ?=-99 Error in W2mag
427-438 F12.8 --- UMAP1-S ?=-99 UMAP axis 1 (S-PLUS only)
440-451 F12.8 --- UMAP2-S ?=-99 UMAP axis 2 (S-PLUS only)
453-455 I3 --- Class-S [0/4]?=-99 HDBSCAN class (S-PLUS) (2)
457-468 F12.8 --- UMAP1-S+W ?=-99 UMAP axis 1 (S-PLUS+WISE)
470-481 F12.8 --- UMAP2-S+W ?=-99 UMAP axis 2 (S-PLUS+WISE)
483-485 I3 --- Class-S+W [-1/4]?=-99 HDBSCAN class (S-PLUS+WISE) (3)
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Note (1): SIMBAD classification in MS cross-match (2" radius).
UNKNOWN = No counterpart.
Note (2): Class_SPLUS: Clustering groups (S-PLUS only) as follows:
0 = QSO-dominated
1 = RR Lyrae/EB*
2 = EB*/Stars
3 = AGN/QSO
4 = QSO/CataclyV*
Note (3): ClassSPLUSWISE: Clustering groups (S-PLUS+WISE) as follows:
0 = EB*/RRLyr-dominated
1 = QSO
2 = AGN/QSO
3 = CataclyV*
4 = QSO
-1 = Noise
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Byte-by-byte Description of file: hasgds.dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- ID Unique source identifier, GDSdNNNNNNNNN
17- 28 F12.8 deg RAdeg Right Ascension (J2000)
30- 41 F12.8 deg DEdeg Declination (J2000)
43- 53 F11.8 mag umag ?=99 S-PLUS u-band PSF-photometry magnitude
55- 65 F11.8 mag e_umag ?=99 Error in u-band magnitude
67- 77 F11.8 mag J0378mag ?=99 S-PLUS J0378 PSF-photometry magnitude
79- 89 F11.8 mag e_J0378mag ?=99 Error in J0378mag
91-101 F11.8 mag J0395mag ?=99 S-PLUS J0395 PSF-photometry magnitude
103-113 F11.8 mag e_J0395mag ?=99 Error in J0395mag
115-125 F11.8 mag J0410mag ?=99 S-PLUS J0410 PSF-photometry magnitude
127-137 F11.8 mag e_J0410mag ?=99 Error in J0410mag
139-149 F11.8 mag J0430mag ?=99 S-PLUS J0430 PSF-photometry magnitude
151-161 F11.8 mag e_J0430mag ?=99 Error in J0430mag
163-173 F11.8 mag gmag ?=99 S-PLUS g-band PSF-photometry magnitude
175-185 F11.8 mag e_gmag ?=99 Error in gmag
187-197 F11.8 mag J0515mag ?=99 S-PLUS J0515 PSF-photometry magnitude
199-209 F11.8 mag e_J0515mag ?=99 Error in J0515mag
211-221 F11.8 mag rmag S-PLUS r-band PSF-photometry magnitude
223-232 F10.8 mag e_rmag Error in rmag
234-244 F11.8 mag J0660mag S-PLUS J0660 PSF-photometry magnitude
246-255 F10.8 mag e_J0660mag Error in J0660mag
257-267 F11.8 mag imag S-PLUS i-band PSF-photometry magnitude
269-278 F10.8 mag e_imag Error in imag
280-290 F11.8 mag J0861mag ?=99 S-PLUS J0861 PSF-photometry magnitude
292-302 F11.8 mag e_J0861mag ?=99 Error in J0861mag
304-314 F11.8 mag zmag S-PLUS z-band PSF-photometry magnitude
316-325 F10.8 mag e_zmag Error in zmag
327-343 A17 --- SimbadType SIMBAD classification (1)
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Note (1): SimbadType: SIMBAD classification in GDS cross-match (1" radius).
UNKNOWN = No counterpart.
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Acknowledgements:
Luis Angel Gutierrez-Soto, gsoto.angel(at)gmail.com
(End) Patricia Vannier [CDS] 31-Jan-2025