J/ApJ/925/76 M33 with LAMOST survey sp. I. PNe & HII regions (Alexeeva+, 2022)
Spectroscopic study of M33 with the LAMOST survey.
I. Chemical gradients from nebulae.
Alexeeva S., Zhao G.
<Astrophys. J., 925, 76 (2022)>
=2022ApJ...925...76A 2022ApJ...925...76A
ADC_Keywords: Abundances; Spectra, optical; Galaxies, nearby; H II regions;
Planetary nebulae
Keywords: Gaseous nebulae ; Triangulum Galaxy ; Chemical abundances ;
Interstellar abundances ; Galaxy chemical evolution ;
Interstellar medium ; Emission nebulae ; Nebulae
Abstract:
Morphological and chemical structures of M33 are investigated with the
LAMOST DR7 survey. Physical parameters; extinction; chemical
composition of He, N, O, Ne, S, Cl, and Ar (where available); and
radial velocities were determined for 110 nebulae (95 HII regions and
15 planetary nebulae) in M33. Among them, 8 planetary nebulae and
55 HII regions in M33 are newly discovered. We obtained the following
O abundance gradients: -0.199-0.030+0.030dex R25-1 (based on
95 HII regions), -0.124-0.036+0.036dex R25-1 (based on
93 HII regions), and -0.207-0.174+0.160dex R25-1 (based on
21 HII regions), utilizing abundances from N2 at O3N2 diagnostics and
the Te-sensitive method, respectively. The He, N, Ne, S, and Ar
gradients resulted in slopes of -0.179-0.146+0.145,
-0.431-0.281+0.282, -0.171-0.239+0.234,
-0.417-0.182+0.174, and -0.340-0.157+0.156, respectively,
utilizing abundances from the Te-sensitive method. Our results confirm
the existence of the negative axisymmetric global metallicity
distribution that is assumed in the literature. We noticed one new WC
star candidate and one transition W-R WN/C candidate. The grand-design
pattern of the spiral structure of M33 is presented.
Description:
The Large sky Area Multi-Object Spectroscopic Telescope (LAMOST) is a
4m telescope located at the Xinglong Observatory northeast of Beijing,
China. We checked 2154 LAMOST low-resolution (R∼1800) spectra at
3700-9099Å from the DR7 release (observed from 2011 December to
2018 October) in the radius of 31.6' from the center of the M33. A
total of 110 high signal-to-noise ratio nebular spectra were selected
for further analysis. They were divided into two groups: HII regions
and PNe.
Objects:
------------------------------------------------------------------------
RA (ICRS) DE Designation(s) (Dist, kpc)
------------------------------------------------------------------------
01 33 50.89 +30 39 36.8 M33 = NAME Triangulum Pinwheel (D=878)
------------------------------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 71 110 Sample of PNe and HII regions in M33 from
LAMOST survey
table3.dat 104 110 The chemical abundances and radial velocities
of nebulae
flux.dat 60 2052 Measured fluxes, fluxes corrected for extinction
for particular ions
--------------------------------------------------------------------------------
See also:
VI/64 : Recombination line intensities for hydrogenic ions (Storey+ 1995)
V/156 : LAMOST DR7 catalogs (Luo+, 2019)
J/ApJ/469/629 : UV-brightest stars of M33 and its nucleus (Massey+ 1996)
J/ApJ/505/793 : New WR star in M33 (Massey+, 1998)
J/PASP/111/685 : HII regions of M33. II. (Hodge+, 1999)
J/A+A/367/498 : Candidate Planetary Nebulae in M 33 (Magrini+, 2001)
J/AJ/126/2867 : Red supergiants in Magellanic Clouds (Massey+, 2003)
J/ApJ/614/167 : Planetary nebulae in M33 (Ciardullo+, 2004)
J/AJ/131/2478 : M31 and M33 UBVRI photometry (Massey+, 2006)
J/ApJS/174/366 : Chandra ACIS survey of M33 (ChaSeM33) (Plucinsky+, 2008)
J/ApJ/675/1213 : Abundances in M33 HII regions (Rosolowsky+, 2008)
J/ApJ/696/729 : Fluxes and abundances of PNe in M33 (Magrini+, 2009)
J/A+A/512/A63 : Abundances of M33 HII regions (Magrini+, 2010)
J/ApJ/733/123 : The Wolf-Rayet content of M33 (NGC 598) (Neugent+, 2011)
J/ApJ/758/133 : Metallicities of M31 HII regions & PNe (Sanders+, 2012)
J/A+A/559/A114 : Updated O3N2 and N2 abundance indicators (Marino+, 2013)
J/A+A/552/A140 : SEDs of M33 HII regions (Relano+, 2013)
J/MNRAS/449/4048 : The Hα rotation curve of M33 (Kam+, 2015)
J/A+A/595/A43 : Photometry of 119 HII regions in M33 (Relano+, 2016)
J/ApJ/842/97 : Spectroscopic obs. of 413 HII regions in M33 (Lin+, 2017)
J/ApJ/923/78 : HII regions in the northern half of M33 (Sawant+, 2021)
J/ApJS/252/21 : Multiwavelength survey of WR stars in LMC (Hung+, 2021)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 A3 --- OType Object type
5- 7 I3 --- Seq [1/110] Running sequence number
9- 27 A19 --- LAMOST LAMOST name (JHHMMSS.ss+DDMMSS.s)
29- 38 A10 "Y/M/D" Date Date of observation (UT)
40- 48 F9.6 deg RAdeg Right ascension in decimal degrees (J2000)
50- 58 F9.6 deg DEdeg Declination in decimal degrees (J2000)
60- 66 A7 --- r_OType Classification reference or
"new" (63 occurrences) (1)
68- 71 A4 --- n_Seq Object type uncertainty for #84 (2)
--------------------------------------------------------------------------------
Note (1): We call regions "new" if there is no previous classification as
an HII region or PN in the literature for objects within the radius
of 2" (the site seeing of the telescope). For regions that were
classified in previous works, we provide references as follows:
ZCH2020 = Zhang et al. (2020RAA....20...97Z 2020RAA....20...97Z)
CDL2004 = Ciardullo et al. (2004ApJ...614..167C 2004ApJ...614..167C)
MCM2000 = Magrini et al. (2000A&A...355..713M 2000A&A...355..713M)
VGHC86 = Viallefond et al. (1986A&AS...64..237V 1986A&AS...64..237V)
DMS93 = Drissen et al. (1993AJ....105.1400D 1993AJ....105.1400D)
BCL74 = Boulesteix et al. (1974A&A....37...33B 1974A&A....37...33B)
RVP2013 = Relano et al. (2013, J/A+A/552/A140)
LHK2017 = Lin et al. (2017, J/ApJ/842/97)
B2011 = Bresolin (2011ApJ...730..129B 2011ApJ...730..129B)
MVM2007 = Magrini et al. (2007A&A...470..865M 2007A&A...470..865M)
CPS87 = Courtes et al. (1987A&A...174...28C 1987A&A...174...28C)
LJD2011 = Lagrois et al. (2011MNRAS.413..705L 2011MNRAS.413..705L)
CS82 = Christian & Schommer (1982ApJS...49..405C 1982ApJS...49..405C)
MOH2006 = Massey et al. (2006, J/AJ/131/2478)
Note (2): The nebula J013340.36+302001.6 (#84) was classified as an HII region
in our study. However, this nebula is located very close to
J013340.37+302001.6, which was classified as a new SNR candidate in
Zhang+ (2020RAA....20...97Z 2020RAA....20...97Z), who employed an additional
classification based on Frew & Parker (2010PASA...27..129F 2010PASA...27..129F).
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 A3 --- OType Object type
5- 7 I3 --- Seq [1/110] Running sequence number
9- 13 F5.3 --- cHb [0.001/0.73] Extinction coefficient, c(Hβ)
15- 20 F6.1 cm-3 ne [1/1000]? Electron density
22- 26 I5 K TOIII [7283/10568]? Electron temperature, [OIII] (3)
28- 32 I5 K TNII [8237/11232]? Electron temperature, [NII] (3)
34- 37 I4 K TOII [6986/6986]? Electron temperature, [OII] (3)
39- 42 F4.2 --- O/H(N2) [8/8.6]? Oxygen abundance derived with N2
diagnostics
44- 47 F4.2 --- O/H(O3) [8.1/8.6]? Oxygen abundance derived with O3N2
diagnostics
49- 52 F4.2 --- O/H [6.3/8.9] Oxygen abundance derived with direct
method
54- 57 F4.2 --- N/H [6.18/8.1]? Nitrogen abundance derived with
direct method
59- 62 F4.2 --- Ne/H [7.3/8.5]? Neon abundance derived with direct
method
64- 67 F4.2 --- S/H [5.9/7]? Sulfur abundance derived with direct
method
69- 72 F4.2 --- Cl/H [4.6/5.2]? Chlorine abundance derived with
direct method
74- 77 F4.2 --- Ar/H [4.9/6.8]? Argon abundance derived with direct
method
79- 83 F5.2 --- He/H [10/11.2]? Helium abundance derived with
direct method from optical recombination lines
85- 88 I4 km/s RV [-120/114] Radial velocity (4)
90- 91 I2 km/s e_RV [0/90] RV standard deviation
93- 97 F5.3 kpc R [0.29/8.1] Distance to the center of M33 (5)
99- 104 F6.4 --- R/R25 [0.04/1.2] R to R25 ratio (6)
--------------------------------------------------------------------------------
Note (3): A value of Te=10000K was assumed to calculate the ionic and
total abundances, when Te is not available.
Note (4): Radial velocity was calculated from Halfa, Hbeta, and doublet
of [SII]6716/6731Å. Systemic velocity of M33, -179km/s, has been
subtracted.
Note (5): With M33 at RA(J2000)=01:33:50.9,DE(J2000)=+30:39:36.8
(from Plucinsky+ 2008, J/ApJS/174/366);
Position angle (major axis)=23° and Inclination=56°
(from Zaritsky+ 1989AJ.....97...97Z 1989AJ.....97...97Z); see Table 2.
Note (6): Assumed an R25 of 28.2 arcmin (de Vaucouleurs 1959ApJ...130..728D 1959ApJ...130..728D).
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Byte-by-byte Description of file: flux.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- Seq [1/110] Running sequence number
5- 23 A19 --- LAMOST LAMOST name (JHHMMSS.ss+DDMMSS.s)
25- 31 F7.2 0.1nm lambda [3726.03/9068.6] Wavelength in Å
33- 40 A8 --- Line Ion identifier
44- 51 F8.3 --- Fline [0.086/1213] Emission line intensities on
scale Hbeta=100
53- 60 F8.3 --- Iline [0.076/1213] Emission line intensities on
scale Hbeta=100 (corrected for extinction)
--------------------------------------------------------------------------------
Acknowledgements:
Alexeeva Sofya [alexeeva at nao.cas.cn]
(End) Emmanuelle Perret [CDS] 30-Aug-2023