J/ApJS/273/22 Subaru BVI photometry of objects in M33's disk (Stonkute+, 2024)
Subaru Suprime-Cam wide-field BVI stellar photometry of the M33 galaxy.
Stonkute R., Vansevicius V.
<Astrophys. J. Suppl. Ser., 273, 22 (2024)>
=2024ApJS..273...22S 2024ApJS..273...22S
ADC_Keywords: Galaxies, nearby; Photometry, UBVRI
Keywords: Spiral galaxies ; Triangulum Galaxy ; Stellar photometry
Abstract:
We have surveyed the complete extent of the disk of M33 --a gas-rich
low-mass dwarf spiral galaxy in the Local Group. The B-, V-, and
I-passband (the Johnson-Cousins system) CCD images (typical seeing
∼0.8") were obtained with the Subaru Telescope equipped with the
Suprime-Cam mosaic camera. The wide-field (∼1.0°x1.5°) catalog
of 803,095 (15≤V≤25) starlike objects, measured using the
point-spread function and aperture photometry techniques, is
presented. We determined the distance modulus of M33 using the tip of
the red giant branch (ITRGB=20.64±0.02) as a reference point of
(m-M)0=24.63±0.02stat±0.06syst (843kpc). We found young
(≲100Myr) stellar populations residing up to the deprojected radius
of ∼10kpc. The scale length of the young main-sequence (MS) star
surface-number density in the range of radial distances from 7 to 9kpc
is 0.53±0.03kpc. The youngest MS stars (≲15Myr) reside up to the
radius of ∼8kpc. This distribution of stellar populations may suggest
an outside-in scenario of recent star formation in the disk of M33.
Description:
Taking into account the large angular size of M33 (∼70' along the
major axis), the Subaru Telescope, equipped with the Prime Focus
Camera (Suprime-Cam), was used to study the stellar content out to the
galaxy disk's outskirts. A single-shot Suprime-Cam mosaic (5x2 CCD
chips; 2kx4k each) covers a field of 34'x27' (scale 0.2"/pixel).
Therefore, to map the entire galaxy, we used eight partly overlapping
pointings of the Suprime-Cam --a grid of 4x2 mosaics (hereinafter the
field) along the major and the minor axes of M33, respectively. Eight
overlapping Suprime-Cam mosaics produced a continuous survey field
centered on the M33 galaxy (Figure 1). We collected photometric data
through B, V, and IC (marked as I throughout) Johnson-Cousins system
filters on 2001 November 20 and 21 (P.I. Nobuo Arimoto).
The Suprime-Cam photometry catalog of 803,095 starlike objects
(15≤V≤25) in the field (62'x95') centered on M33 is presented in
Table 2.
Objects:
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RA (ICRS) DE Designation(s)
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01 33 50.89 +30 39 36.6 M33 = NAME Triangulum Galaxy
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 109 803095 The Suprime-Cam stellar photometry catalog in
the M33 field
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See also:
J/MNRAS/371/1405 : Variables in M33 (Hartman+, 2006)
J/AJ/131/2478 : M31 and M33 UBVRI photometry (Massey+, 2006)
J/A+A/533/A91 : Deep VI imaging in outer regions of M33 (Grossi+, 2011)
J/ApJS/214/19 : Suprime-Cam wide-field photometry of Leo A (Stonkute+, 2014)
J/MNRAS/449/4048 : The Hα rotation curve of M33 (Kam+, 2015)
J/ApJ/868/55 : Structure of M31 halo. II. PAndAS (McConnachie+, 2018)
J/ApJS/253/53 : PHATTER. I. HST obs. of stars in M33 (Williams+, 2021)
J/A+A/667/A87 : Edges of galaxies. Limits of star formation (Chamba+, 2022)
J/A+A/660/A79 : BHeB stars in the Leo A galaxy (Lescinskaite+, 2022)
J/ApJS/259/6 : Dwarf irregular galaxy Leo A. II. (Stonkute+, 2022)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 18 A18 --- ID Source identifier (M33rwDDdddd+DDdddd)
20- 27 F8.5 deg RAdeg [22.5/24.5] Right Ascension (J2000) (1)
29- 37 F9.5 deg DEdeg [29.7/31.7] Declination (J2000) (1)
39- 44 F6.3 mag Bmag [15.17/26.8]? The Johnson-Cousins B band
apparent magnitude
46- 50 F5.3 mag e_Bmag [0/0.25]? The 1σ error of Bmag
52- 58 F7.3 --- ShB [-23.2/9.7]? The image-sharpness of object
(DAOPHOT) in Bmag; see Figure 3
60- 61 I2 --- o_Bmag [2/10]? Number of Bmag observations (2)
63- 68 F6.3 mag Vmag [15/25.9] The Johnson-Cousins V band apparent
magnitude
70- 74 F5.3 mag e_Vmag [0/0.3] The 1σ error of Vmag
76- 82 F7.3 --- ShV [-20.7/10.4] The image-sharpness of object
(DAOPHOT) in Vmag; see Figure 3
84- 85 I2 --- o_Vmag [2/10] Number of Vmag observations (2)
87- 92 F6.3 mag Imag [15/25.6]? The Johnson-Cousins I band apparent
magnitude
94- 98 F5.3 mag e_Imag [0/0.3]? The 1σ error of Imag
100- 106 F7.3 --- ShI [-15.2/6.6]? The image-sharpness of object
(DAOPHOT) in Imag; see Figure 3
108- 109 I2 --- o_Imag [1/10]? Number of Imag observations (2)
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Note (1): Equatorial coordinates in the USNO-B1.0 catalog system.
Note (2): Numbers of measurements in individual passbands; in cases of more
than 10 measurements a number 10 is provided.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 31-Dec-2024