J/ApJ/982/33 Scylla+METAL combined photometry master catalog (Lindberg+, 2025)
Scylla. IV. Intrinsic Stellar Properties and Line-of-sight Dust Extinction
Measurements toward 1.5 Million Stars in the SMC and LMC.
Lindberg C.W., Murray C.E., Yanchulova Merica-Jones P., Bot C.,
Burhenne C., Choi Y., Clark C.J.R., Cohen R.E., Gilbert K.M., Goldman S.R.,
Gordon K.D., Hirschauer A.S., McQuinn K.B.W., Roman-Duval J.C.,
Sandstrom K.M., Tarantino E., Williams B.F.
<Astrophys. J. 982, 33 (2025)>
=2025ApJ...982...33L 2025ApJ...982...33L (SIMBAD/NED BibCode)
ADC_Keywords: Magellanic Clouds ; Photometry, infrared
Keywords: Magellanic Clouds - Hubble Space Telescope - Stellar populations -
Interstellar medium
Abstract:
By analyzing the spectral energy distributions (SEDs) of resolved
stars in nearby galaxies, we can constrain their stellar properties
and line-of-sight dust extinction. From the Scylla survey, we obtain
ultraviolet to near-infrared photometry from Wide Field Camera 3 on
board the Hubble Space Telescope for more than 1.5 million stars in
the SMC and LMC. We use the Bayesian Extinction and Stellar Tool
(BEAST) to analyze the multiband SEDs of these sources and
characterize their initial masses, ages, metallicities, distances, and
line-of-sight extinction properties (e.g., AV, RV). We apply quality
cuts and perform validation simulations to construct a catalog of over
550000 stars with high-reliability SED fits, which we use to analyze
the stellar content and extinction properties of the SMC and LMC. We
detect stars with masses as low as 0.6M☉. BEAST stellar age
distributions show a jump in observed stars around 6Gyr ago, which
agrees with star formation histories. Extinctions (AV) in both
galaxies follow a log-normal distribution. We compare AV with
ancillary gas and dust tracers like HI, Halpha, and far-infrared (FIR)
dust emission and find positive correlations on a field-by-field
basis. We convert observed AV to predicted dust surface densities
using the Draine et al. model and find AV-based dust surface densities
are a factor of ∼2.5 lower than observed FIR-based dust surface
densities, a correction factor similar to other studies.
Description:
This catalog combines per-source DOLPHOT photometry and BEAST stellar
and dust parameter fits for stars in the Small and Large Magellanic
Clouds (SMC and LMC), drawn from the Scylla pure-parallel HST survey
(PIDs 15891, 16235, 16786; PI: Murray) and the METAL survey (PID
14675; PI: Roman-Duval; Roman-Duval et al., 2014ApJ...797...86R 2014ApJ...797...86R).
The catalog contains 1573594 sources combined from the Complete
Catalogs (CC) of 89 individual fields (57 Scylla + 32 METAL). All
BEAST-fit sources above the detection threshold are included; no
quality cuts have been applied. A boolean 'reliable' flag indicates
sources that pass the High-Reliability Catalog (HRC) quality cuts
described in Lindberg et al. 2025ApJ...982...33L 2025ApJ...982...33L (L25); users may
apply their own cuts using the included DOLPHOT diagnostic columns.
Observations were obtained with the HST/WFC3 instrument in up to seven
broadband filters: F225W, F275W, F336W, F475W, F814W, F110W, F160W.
Not all fields were observed in all filters; per-filter photometry
columns contain NaN for filters not observed in a given source's
field. See Murray for the per-field filter coverage.
BEAST (Bayesian Extinction And Stellar Tool; Gordon et al.
2016ApJ...826..104G 2016ApJ...826..104G) posterior expectation values (Exp) are reported
for 13 dust and stellar parameters. The full per-source BEAST
posterior products (Best, p16, p50, p84 statistics, model predicted
fluxes, etc.) are available in the per-field BEAST catalogs at
https://archive.stsci.edu/hlsp/scylla (DOI 10.17909/mk54-kg51).
FILE STRUCTURE
scyllaphotmaster.fits is a multi-extension FITS file:
HDU 0 PRIMARY Empty primary HDU containing metadata keywords
HDU 1 PHOT Binary table with 1,573,594 rows x 97 columns
HDU 0 - PRIMARY metadata keywords:
HLSPID Project identifier ('SCYLLA')
HLSPLEAD Lead author
DOI Digital Object Identifier
TELESCOP Telescope ('HST')
INSTRUME Instrument ('WFC3')
FILTER Filter(s) ('MULTI')
RADESYS Coordinate reference system ('ICRS')
LICENSE Data license
CATTYPE Catalog type description
NFIELDS Number of fields combined (89)
NSOURCES Total number of sources (1573594)
Source data:
Per-field BEAST catalogs (CC extension) from the Scylla MAST HLSP archive:
https://archive.stsci.edu/hlsp/scylla
DOI 10.17909/mk54-kg51
Combined catalog construction:
- 89 per-field Complete Catalogs (CC) concatenated using
astropy.table.vstack
- Galaxy, Field, FieldID columns added from each field's HLSP metadata
- Dist column converted from BEAST native units (pc) to kpc
- reliable flag converted to int 0/1 (was boolean)
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
photcat.dat 996 1573594 Scylla + METAL combined photometry master catalog
scyllapm.fits 2880 260634 Fits version of the catalog
--------------------------------------------------------------------------------
See also:
J/ApJ/871/151 : METAL Hubble program. I. Initial results (Roman-Duval+, 2019)
Byte-by-byte Description of file: photcat.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 A3 --- Galaxy Host galaxy (LMC or SMC) (Galaxy)
5- 10 A6 --- Field Short field name (M01-M32 for METAL;
LMC_N or SMC_N for Scylla) (Field)
12- 34 A23 --- FieldID Long field identifier (e.g.,
'14675_LMC-13361nw-11112') (FieldID)
36- 65 A30 --- Name IAU-style source designation,
SCYLLA JHHMMSS.ssss+DDMMSS.sss (Name)
67- 81 F15.11 deg RAdeg Right Ascension (ICRS) at Ep=2000 (RAdeg)
83- 97 F15.11 deg DEdeg Declination (ICRS) at Ep=2000 (DEdeg)
99-110 E12.6 ct/s F225Wrate ?=- DOLPHOT count rate for F225W filter
(F225W_rate)
112-123 E12.6 ct/s e_F225Wrate ?=- DOLPHOT count rate error for F225W filter
(eF225Wrate)
125-131 F7.3 mag F225Wmag ?=- Vega magnitude for F225W filter
(F225Wmag)
133-139 F7.3 mag F225Wstd [99.999]?=- Photometric standard deviation
for F225W filter (F225W_std)
141-145 F5.3 mag e_F225Wmag ?=- Vega magnitude error for F225W filter
(e_F225Wmag)
147-151 F5.2 --- F225Wchi ?=- Chi value from DOLPHOT PSF fit for F225W
filter (F225W_chi)
153-163 F11.6 --- F225WSNR ?=- Signal-to-noise ratio for F225W filter
(F225W_SNR)
165-173 F9.6 --- F225Wsharp ?=- DOLPHOT sharpness parameter for F225W
filter (F225W_sharp)
175-183 F9.6 --- F225Wround ?=- DOLPHOT roundness parameter for F225W
filter (F225W_round)
185-192 F8.6 mag F225Wcrowd ?=- DOLPHOT crowding parameter for F225W
filter (F225W_crowd)
194 I1 --- F225WFlag ?=- DOLPHOT quality flag (0 = no issues)
for F225W filter (F225W_flag)
196-207 E12.6 ct/s F275Wrate ?=- DOLPHOT count rate for F275W filter
(F275W_rate)
209-220 E12.6 ct/s e_F275Wrate ?=- DOLPHOT count rate error for F275W filter
(eF275Wrate)
222-228 F7.3 mag F275Wmag ?=- Vega magnitude for F275W filter
(F275Wmag)
230-236 F7.3 mag F275Wstd [-]?=- Photometric standard deviation
for F275W filter (F275W_std)
238-242 F5.3 mag e_F275Wmag ?=- Vega magnitude error for F275W filter
(e_F275Wmag)
244-248 F5.2 --- F275Wchi ?=- Chi value from DOLPHOT PSF fit for F275W
filter (F275W_chi)
250-260 F11.6 --- F275WSNR ?=- Signal-to-noise ratio for F275W filter
(F275W_SNR)
262-270 F9.6 --- F275Wsharp ?=- DOLPHOT sharpness parameter for F275W
filter (F275W_sharp)
272-280 F9.6 --- F275Wround ?=- DOLPHOT roundness parameter for F275W
filter (F275W_round)
282-289 F8.6 mag F275Wcrowd ?=- DOLPHOT crowding parameter for F275W
filter (F275W_crowd)
291 I1 --- F275WFlag ?=- DOLPHOT quality flag (0 = no issues)
for F275W filter (F275W_flag)
293-304 E12.6 ct/s F336Wrate ?=- DOLPHOT count rate for F336W filter
(F336W_rate)
306-317 E12.6 ct/s e_F336Wrate ?=- DOLPHOT count rate error for F336W filter
(eF336Wrate)
319-325 F7.3 mag F336Wmag ?=- Vega magnitude for F336W filter
(F336Wmag)
327-333 F7.3 mag F336Wstd [-]?=- Photometric standard deviation
for F336W filter (F336W_std)
335-339 F5.3 mag e_F336Wmag ?=- Vega magnitude error for F336W filter
(e_F336Wmag)
341-345 F5.2 --- F336Wchi ?=- Chi value from DOLPHOT PSF fit for F336W
filter (F336W_chi)
347-357 F11.6 --- F336WSNR ?=- Signal-to-noise ratio for F336W filter
(F336W_SNR)
359-367 F9.6 --- F336Wsharp ?=- DOLPHOT sharpness parameter for F336W
filter (F336W_sharp)
369-377 F9.6 --- F336Wround ?=- DOLPHOT roundness parameter for F336W
filter (F336W_round)
379-386 F8.6 mag F336Wcrowd ?=- DOLPHOT crowding parameter for F336W
filter (F336W_crowd)
388 I1 --- F336WFlag ?=- DOLPHOT quality flag (0 = no issues)
for F336W filter (F336W_flag)
390-401 E12.6 ct/s F475Wrate DOLPHOT count rate for F475W filter
(F475W_rate)
403-414 E12.6 ct/s e_F475Wrate DOLPHOT count rate error for F475W filter
(eF475Wrate)
416-422 F7.3 mag F475Wmag ?=- Vega magnitude for F475W filter
(F475Wmag)
424-430 F7.3 mag F475Wstd [-]?=- Photometric standard deviation for
F475W filter (F475W_std)
432-436 F5.3 mag e_F475Wmag ?=- Vega magnitude error for F475W filter
(e_F475Wmag)
438-442 F5.2 --- F475Wchi Chi value from DOLPHOT PSF fit for F475W
filter (F475W_chi)
444-455 E12.6 --- F475WSNR Signal-to-noise ratio for F475W filter
(F475W_SNR)
457-465 F9.6 --- F475Wsharp DOLPHOT sharpness parameter for F475W filter
(F475W_sharp)
467-475 F9.6 --- F475Wround DOLPHOT roundness parameter for F475W filter
(F475W_round)
477-484 F8.6 mag F475Wcrowd DOLPHOT crowding parameter for F475W filter
(F475W_crowd)
486 I1 --- F475WFlag ?=- DOLPHOT quality flag (0 = no issues)
for F475W filter (F475W_flag)
488-499 E12.6 ct/s F814Wrate DOLPHOT count rate for F814W filter
(F814W_rate)
501-512 E12.6 ct/s e_F814Wrate DOLPHOT count rate error for F814W filter
(eF814Wrate)
514-520 F7.3 mag F814Wmag ?=- Vega magnitude for F814W filter
(F814Wmag)
522-528 F7.3 mag F814Wstd [-]?=- Photometric standard deviation for
F814W filter (F814W_std)
530-534 F5.3 mag e_F814Wmag ?=- Vega magnitude error for F814W filter
(e_F814Wmag)
536-540 F5.2 --- F814Wchi Chi value from DOLPHOT PSF fit for F814W
filter (F814W_chi)
542-553 E12.6 --- F814WSNR Signal-to-noise ratio for F814W filter
(F814W_SNR)
555-563 F9.6 --- F814Wsharp DOLPHOT sharpness parameter for F814W filter
(F814W_sharp)
565-573 F9.6 --- F814Wround DOLPHOT roundness parameter for F814W filter
(F814W_round)
575-582 F8.6 mag F814Wcrowd DOLPHOT crowding parameter for F814W filter
(F814W_crowd)
584 I1 --- F814WFlag ?=- DOLPHOT quality flag (0 = no issues)
for F814W filter (F814W_flag)
586-597 E12.6 ct/s F110Wrate ?=- DOLPHOT count rate for F110W filter
(F110W_rate)
599-610 E12.6 ct/s e_F110Wrate ?=- DOLPHOT count rate for F110W filter
(eF110Wrate)
612-618 F7.3 mag F110Wmag ?=- Vega magnitude for F110W filter
(F110Wmag)
620-626 F7.3 mag F110Wstd [-]?=- Photometric standard deviation
for F110W filter (F110W_std)
628-635 F8.6 mag e_F110Wmag ?=- Vega magnitude error for F110W filter
(e_F110Wmag)
637-642 F6.2 --- F110Wchi ?=- Chi value from DOLPHOT PSF fit for F110W
filter (F110W_chi)
644-655 E12.6 --- F110WSNR ?=- Signal-to-noise ratio for F110W filter
(F110W_SNR)
657-665 F9.6 --- F110Wsharp ?=- DOLPHOT sharpness parameter for F110W
filter (F110W_sharp)
667-675 F9.6 --- F110Wround ?=- DOLPHOT roundness parameter for F110W
filter (F110W_round)
677-684 F8.6 mag F110Wcrowd ?=- DOLPHOT crowding parameter for F110W
filter (F110W_crowd)
686-687 I2 --- F110WFlag ?=- DOLPHOT quality flag (0 = no issues)
for F110W filter (F110W_flag)
689-700 E12.6 ct/s F160Wrate ?=- DOLPHOT count rate for F160W filter
(F160W_rate)
702-713 E12.6 ct/s e_F160Wrate ?=- DOLPHOT count rate error for F160W filter
(eF160Wrate)
715-721 F7.3 mag F160Wmag ?=- Vega magnitude for F160W filter
(F160Wmag)
723-729 F7.3 mag F160Wstd [-]?=- Photometric standard deviation
for F160W filter (F160W_std)
731-738 F8.6 mag e_F160Wmag ?=- Vega magnitude error for F160W filter
(e_F160Wmag)
740-745 F6.2 --- F160Wchi ?=- Chi value from DOLPHOT PSF fit for F160W
filter (F160W_chi)
747-758 E12.6 --- F160WSNR ?=- Signal-to-noise ratio for F160W filter
(F160W_SNR)
760-768 F9.6 --- F160Wsharp ?=- DOLPHOT sharpness parameter for F160W
filter (F160W_sharp)
770-778 F9.6 --- F160Wround ?=- DOLPHOT roundness parameter for F160W
filter (F160W_round)
780-787 F8.6 mag F160Wcrowd ?=- DOLPHOT crowding parameter for F160W
filter (F160W_crowd)
789-790 I2 --- F160WFlag ?=- DOLPHOT quality flag (0 = no issues)
for F160W filter (F160W_flag)
792 I1 --- reliable [0,1] HRC quality flag (reliable) (1)
794-808 F15.12 mag Av V-band dust extinction (Av)
810-823 F14.12 --- Rv Total-to-selective extinction ratio
(R_V = A_V / E(B-V)) (Rv)
825-838 F14.12 --- fA Fractional contribution of SMC-like dust
component A (fA) (2)
840-853 F14.12 [K] logTeff Log10 of effective temperature (logTe)
855-869 F15.12 [Lsun] logL Log10 of bolometric luminosity (logL)
871-884 F14.12 [cm/s2] logg Log10 of surface gravity (logg)
886-900 F15.12 [yr] logAge Log10 of stellar age (logAge)
902-916 F15.12 Msun Mini Initial (zero-age main sequence) stellar mass
(Mini)
918-932 F15.12 Msun Mact Current (actual) stellar mass (Mact)
934-947 F14.12 --- Z Stellar metallicity as mass fraction
(Z☉∼0.014; BEAST grid range
0.0001-0.03) (Z)
949-963 F15.12 mag mbol Bolometric magnitude (mbol)
965-980 F16.12 Rsun Rad Stellar radius (Rad)
982-996 F15.12 kpc Dist Distance to source (Dist)
--------------------------------------------------------------------------------
Note (1): HRC quality flag as follows:
1 = passes strict HRC quality cuts (highly reliable)
0 = does not pass strict cuts (use with caution)
Note (2): Fractional contribution of SMC-like dust component A
(Gordon et al., 2003ApJ...594..279G 2003ApJ...594..279G) from
1 = pure SMC-like dust to 0 = pure MW-like dust.
--------------------------------------------------------------------------------
Acknowledgements:
Christina Lindberg, christina.lindberg(at)cfa.harvard.edu
License: CC-BY-4.0
References:
Lindberg et al., 2025ApJ...982...33L 2025ApJ...982...33L,
Scylla IV: Intrinsic stellar properties and line-of-sight dust
extinction measurements towards 1.5 million stars in the SMC and LMC
Murray et al., 2024ApJS..271...38H 2024ApJS..271...38H,
Scylla I: Survey overview and description of photometric data products
Gordon et al., 2016ApJ...826..104G 2016ApJ...826..104G,
BEAST: Bayesian Extinction and Stellar Tool
Gordon et al., 2003ApJ...594..279G 2003ApJ...594..279G,
Quantitative comparison of SMC, LMC, and Milky Way extinction curves
Roman-Duval et al., 2019ApJ...871..151R 2019ApJ...871..151R, Cat. J/ApJ/871/151,
METAL: Metal Evolution, Transport, and Abundance in the LMC survey
Dolphin, 2002MNRAS.332...91D 2002MNRAS.332...91D,
DOLPHOT: Stellar photometry package for HST
(End) Patricia Vannier [CDS] 28-May-2026