Date and Time of the Query: 2019-04-20 T03:11:30 PDT
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You have selected the following parameters to search on:

Parameters for Distances and Cosmology: Ho= 73.0; Ωmatter = 0.27; Ωvacuum = 0.73;
Derived Quantities use a Redshift corrected to a Reference Frame defined by the 3K CMB

NED results for object NGC 3998

1 objects found in NED.    


 Row          Object Name                 EquJ2000.0       Object  Velocity/Redshift    Mag./  Separ.               Number of                                 Row 
 No.     (* => Essential Note)       RA               DEC  Type     km/s       z   Qual Filter arcmin Refs Notes Phot Posn Vel/z Diam Assoc Images   Spectra  No. 
1    NGC 3998                       11h57m56.1s +55d27m13s G        1048  0.003496      11.61    ...   506    22  164   32    27    7     0 Retrieve Retrieve 1   

Detailed information for each object

Object No. 1 - NGC 3998

INDEX for NGC 3998
Essential Data (jump to sub-section of this query report):

   Essential Note    
   Basic Data   
   Quantities Derived from Redshift    
   Redshift-Independent Distances
   Quick-Look Photometry and Luminosities
   Quick-Look Angular and Physical Sizes
   Foreground Galactic Extinction    
   External Services
Detailed Data (NED queries):

164 Photometric data point(s) and SED   
Redshift-Independent Distances
506 Reference(s)   
32 Position data point(s)
27 Redshift data point(s)   
7 Diameter data point(s)   
22 Note(s)   
UGC data    
RC3 data    


Object Names Type Object Names Type
NGC 3998G 1RXS J115756.1+552717 XrayS
UGC 06946 G 2PBC J1158.1+5527 XrayS
CGCG 269-025 G 2XMM J115756.1+552714 XrayS
CGCG 1155.3+5543 G 2XMMp J115756.1+552714 XrayS
MCG +09-20-046 G 1XMM J115756.2+552711 XrayS
2MASX J11575616+5527128 IrS 1AXG J115757+5527 XrayS
2MASS J11575612+5527128 IrS 1ES 1155+557 XrayS
IRAS F11553+5543 IrS XSS J11570+5514 XrayS
LDCE 0867 NED055 G CXO J115756.11+552713.1 XrayS
HDCE 0706 NED021 G SWIFT J1157.8+5529 XrayS
LQAC 179+055 007 G SWIFT J1158.0+5526 XrayS
CGRaBS J1157+5527 G LGG 241:[G93] 007 G
HOLM 310A G NGC 3998:[R97] 09 XrayS
NSA 140507 G [M98j] 170 NED27 G
PGC 037642 G RX J1157.9+5527:[BEV98] 001 G
RBS 1053 G NGC 3998:[RW2000] X-02 XrayS
SSTSL2 J115756.11+552712.8 IrS [VCV2001] J115756.1+552713 G
UZC J115756.2+552713 G RX J1157.9+5527:[ZEH2003] 01 G
87GB 115521.8+554353 RadioS[SRM2005] J115756.13+552712.9 G
87GB[BWE91] 1155+5543 RadioSNGC 3998:[LB2005] X01 XrayS
[WB92] 1155+5543 RadioS[VCV2006] J115756.1+552713 G
NVSS J115756+552712 RadioS[HRT2007] J115757+552713 RadioS
6C B115520.5+554340 RadioS[GMM2009b] 32 G
CRATES J1157+5527 RadioSNGC 3998:[L2011a] X0001 XrayS
CRATES J115756.13+552712.9 RadioSv2MCG 47:[DMP2012] 1 G
GB6 J1157+5527 RadioS[AHG2014] B165 G
RGB J1157+554 RadioS[MGD2014] 1155.3+5543 RadioS
VIPS 0499 RadioSUMa Cluster:[PRL2014] U084 G
VIPS J11579+5527 RadioS    
CXO J115756.1+552713 XrayS    
RX J1157.9+5527 XrayS    

COORDINATES for NGC 3998 (Back to INDEX)

Position Reference:2011AJ....142...89P

Reference    Frame     Longitude    Latitude        RA           DEC      Uncertainty Ellipse (arcsec)
                       (degrees)   (degrees)                              Semimajor Semiminor  PA(deg)
Equatorial (B1950.0) 178.8373159  55.7318789 11h55m20.9558s +55d43m54.764s  1.75E-03  1.00E-03   90
Equatorial (J2000.0) 179.4838888  55.4535894 11h57m56.1333s +55d27m12.922s  1.75E-03  1.00E-03   90
Ecliptic   (B1950.0) 148.9222193  48.9062161                              1.75E-03  1.00E-03   53
Ecliptic   (J2000.0) 149.6273773  48.9091136                              1.75E-03  1.00E-03   53
Galactic             138.1723509  60.0634376                              1.75E-03  1.00E-03  114
SuperGalactic         59.9367799   5.0743481                              1.75E-03  1.00E-03   21
Additional detailed measurements with references are also available by clicking below:
32 Position data point(s)


11 Distances found in NED View 11 Individual Distance Measurement(s) for NGC 3998

Summary Statistics computed by NED from 11 Distance(s) in the literature:
NOTE: These summary statistics are provided for "quick-look" reference only;
they are based exclusively on original values, as published.
No homogenization or corrections have been applied.

NGC 3998 Distance Modulus
Metric Distance
Mean 31.33 20.075
Std. Dev. 0.92 8.887
Min. 29.80 9.120
Max. 32.92 38.400
Median 31.26 17.900

TypeAs PublishedNED HomogenizedFlagReference Code
HierarchyRGin a radial-velocity based grouping...1998Afz....41..308M
KinematicsHI line widthHI line width...1985A&A...142....1K
Galaxy MorphologySA0^0(r)?SA0^0(r)?...1991RC3.9.C...0000d
Activity TypeFlat-Spectrum Radio Source,Flat-Spectrum Radio Source...2007ApJS..171...61H
Distance IndicatorTully-FisherTully-Fisher...2007A&A...465...71T
29 Detailed Classification(s)

Galactic Extinction from the Schlafly & Finkbeiner 2011, Appendix; 2011ApJ...737..103S (SF11) recalibration 
of the Schlegel, Finkbeiner & Davis 1998, Appendix B; 1998ApJ...500..525S (SFD98) infrared-based dust map.
The map is based on dust emission from COBE/DIRBE and IRAS/ISSA;
the recalibration assumes a Fitzpatrick (1999PASP..111...63F) reddening law with Rv = 3.1 and different source spectrum than SFD98.

L a n d o l tS D S SU K I R T
Filter [µm]U (0.35)B (0.43)V (0.54)R (0.64)I (0.80)u (0.36)g (0.47)r (0.62)i (0.75)z (0.89)J (1.25)H (1.66)K (2.19)L' (3.78)
Aλ [mag]0.0710.0590.0450.0360.0250.0690.0540.0370.0280.0210.0120.0070.0050.003
Show/Hide Aλ magnitudes in all 88 photometric bands based on SF11
For completeness, we include the original SFD98 values:
L a n d o l tS D S SU K I R T
Filter [µm]U (0.34)B (0.44)V (0.54)R (0.65)I (0.81)u (0.35)g (0.49)r (0.63)i (0.78)z (0.93)J (1.27)H (1.67)K (2.22)L' (3.81)
Aλ [mag]0.0870.0690.0530.0430.0310.0820.0610.0440.0330.0240.0140.0090.0060.002

Galactic Extinction based on H I Column Densities and Galaxy Counts
(Burstein & Heiles; 1982AJ.....87.1165B) assuming Rv = 3.1:
AB = 0.000 mag
See Notes on Galactic Extinction for important caveats.

BASIC DATA for NGC 3998 (Back to INDEX)
Helio. Radial Velocity     :      1048 +/-        5 km/s      
Redshift                   :  0.003496 +/- 0.000017        2011MNRAS.413..813C
Major Diameter (arcmin)    :   2.7
Minor Diameter (arcmin)    :   2.2
Magnitude and Filter       : 11.61
Classifications            : SA(r)0^0^?;Sy1;LINER

NOTE: This information is indicative only. With the exception of the
      redshift they are unreferenced and highly inhomogeneous as to
      their origin. The Radial Velocity (when available) is computed
      from the listed redshift. The remaining values are designed to
      orient the user with a quick-look, overall assessment of the
      general properties of the object in question. They are not
      averages nor are they standardized in any way.
Additional detailed measurements with references are also available by clicking below:
27 Redshift data point(s)      164 photometric data point(s)      7 Diameter data point(s)      

Calculated and Corrected Velocities
V (Heliocentric)           :    1048 +/-      5 km/s      2011MNRAS.413..813C
V (Kinematic LSR)          :    1056 +/-      5 km/s      1986MNRAS.221.1023K
V (Galactocentric GSR)     :    1128 +/-      6 km/s      1991RC3.9.C...0000d
V (Local Group)            :    1140 +/-      8 km/s      1996AJ....111..794K
V (3K CMB)                 :    1216 +/-     13 km/s      1996ApJ...473..576F
V (Virgo Infall only)      :    1420 +/-     21 km/s      2000ApJ...529..786M
V (Virgo + GA only)        :    1510 +/-     22 km/s      2000ApJ...529..786M
V (Virgo + GA + Shapley)   :    1519 +/-     22 km/s      2000ApJ...529..786M

Hubble Flow Distance and Distance Modulus (where Ho =   73.0 +/-   5 km/sec/Mpc)
D (Galactocentric GSR)     :    15.5 +/-    1.1 Mpc      (m-M) = 30.94 +/- 0.15 mag
D (Local Group)            :    15.6 +/-    1.1 Mpc      (m-M) = 30.97 +/- 0.15 mag
D (3K CMB)                 :    16.7 +/-    1.2 Mpc      (m-M) = 31.11 +/- 0.15 mag
D (Virgo Infall only)      :    19.4 +/-    1.4 Mpc      (m-M) = 31.44 +/- 0.15 mag
D (Virgo + GA only)        :    20.7 +/-    1.5 Mpc      (m-M) = 31.58 +/- 0.15 mag
D (Virgo + GA + Shapley)   :    20.8 +/-    1.5 Mpc      (m-M) = 31.59 +/- 0.15 mag

Scale at Hubble Flow Distances
Scale (Galactocentric GSR) :      75 pc/arcsec =  0.075 kpc/arcsec =   4.49 kpc/arcmin =   0.27 Mpc/degree
Scale (Local Group)        :      76 pc/arcsec =  0.076 kpc/arcsec =   4.54 kpc/arcmin =   0.27 Mpc/degree
Scale (3K CMB)             :      81 pc/arcsec =  0.081 kpc/arcsec =   4.84 kpc/arcmin =   0.29 Mpc/degree
Scale (Virgo Infall only)  :      94 pc/arcsec =  0.094 kpc/arcsec =   5.66 kpc/arcmin =   0.34 Mpc/degree
Scale (Virgo + GA only)    :     100 pc/arcsec =  0.100 kpc/arcsec =   6.02 kpc/arcmin =   0.36 Mpc/degree
Scale(Virgo + GA + Shapley):     101 pc/arcsec =  0.101 kpc/arcsec =   6.05 kpc/arcmin =   0.36 Mpc/degree

To Search for Nearby Objects (Physical Companions): Enter Your Preferred Values and click on "Submit Environment Search" button
Search for Objects within +/-arcmin where 100 kpc = 16.517 arcmin and Selected Redshift, defined by the Velocity Range: from to km/sec where V(Heliocentric) = 1048 km/sec
Cosmology-Corrected Quantities [Ho = 73.00 km/sec/Mpc, Ωmatter = 0.27, Ωvacuum = 0.73] [Redshift 0.004055 as corrected to the Reference Frame defined by the 3K Microwave Background Radiation] Luminosity Distance : 16.7 Mpc (m-M) = 31.11 mag Angular-Size Distance : 16.6 Mpc (m-M) = 31.10 mag Co-Moving Radial Distance : 16.6 Mpc (m-M) = 31.11 mag Co-Moving Tangential Dist. : 16.6 Mpc (m-M) = 31.11 mag Co-Moving Volume : 1.93e-05 Gpc^3 Light Travel-Time : 0.054 Gyr Age at Redshift 0.004055 : 13.245 Gyr Age of Universe : 13.299 Gyr Scale (Cosmology Corrected): 80 pc/arcsec = 0.080 kpc/arcsec = 4.82 kpc/arcmin = 0.29 Mpc/degree Surface Brightness Dimming : Flux Density per Unit Area = 0.98394; Magnitude per Unit Area = 0.01757 mag
To change Cosmological Input Parameters for Derived Quantities: Enter Your Preferred Values and click on "Submit Changed Hubble Parameters for this object" button
Correct Redshift To the Reference Frame defined by: as Input for Calculation of the Distances and Cosmology-Corrected Quantities


The brightest flux in each of the following spectral regions, when available:
Gamma-Ray (ν > 2E19 Hz); X-Ray (2E19 Hz > ν > 2E16 Hz); Ultraviolet (2E16 Hz > ν > 9E14 Hz); Visual (9E14 Hz > ν > 3E14 Hz);
Near-Infrared (3E14 Hz > ν > 6E13 Hz); Mid-Infrared (6E13 Hz > ν > 7.5E12 Hz); Far-Infrared (7.5E12 Hz > ν > 1E12 Hz);
Sub-Millimeter (1E12 Hz > ν > 3E11 Hz); Millimeter (3E11 Hz > ν > 3E10 Hz); Radio (3E10 Hz > ν).

Band Apparent Mag or Flux Refcode Absolute Mag or νLν [W] νLν [L(Bolometric)]
Gamma-Ray14-195 keV (Swift) 3.03E-11 +/- 0.48E-11 erg/s/cm^2^ 2010ApJS..186..378T 1.46E+35 +/- 4.54E+34 [W] 3.81E+08 +/- 1.18E+08
X-Ray15-150 keV (Swift) 1.4e-11 +/- 8.0e-12 erg/cm^2^/s 2010A&A...524A..64C 6.76E+34 +/- 4.26E+34 [W] 1.76E+08 +/- 1.11E+08
Ultravioletm(2000) 13.3 +/- 0.7 mag 1987A&A...180...12D-18.03 +/- 0.97 [mag] 4.08E+08 +/- 3.84E+08
VisualF547M (HST/WFPC2) 3.10E-12 erg cm^-2^ s^-1^ 2006A&A...453...27C 1.50E+34 [W] 3.89E+07
Near-InfraredH 7.584 +/- 0.008 mag 20032MASX.C.......:-23.75 +/- 0.67 [mag] 2.16E+10 +/- 5.78E+09
Mid-Infrared25 microns (IRAS) 1.594E-01 +/- 15 % Jy 1990IRASF.C...0000M 9.20E+34 +/- 2.73E+34 [W] 2.39E+08 +/- 7.11E+07
Far-Infrared100 microns (IRAS) 1.150 +/- 0.124 Jy 1994PrivC.U..J....K 1.66E+35 +/- 4.79E+34 [W] 4.33E+08 +/- 1.25E+08
Radio4.86 GHz (VLA) 302 milliJy 2012AJ....143...78K 7.08E+31 [W] 1.84E+05
NOTE: The above quantities are derived using an estimated Distance Modulus of (31.33 +/- 0.92) mag corresponding to
a Metric Distance of (20.075 +/- 8.887) Mpc using the Average NED-D value.
The quantities quoted above have not necessarily been corrected for foreground extinction, and no K-Corrections have been applied.

View details and SED for 164 Photometric data point(s) available in NED.


The largest diameters in the Visual and Near-Infrared spectral regions, when available:

Passband Apparent Major Axis
(2a) [arcsec]
Apparent Minor Axis
(2b) [arcsec]
Reference Level RefcodePhysical Major Axis
(2a) [kpc]
Physical Minor Axis
(2b) [kpc]
POSS1 103a-O 180.00149.40140 About 25.0 B-mag arcsec^-2^ 1973UGC...C...0000N17.5214.54
K_s (2MASS "total") 190.60148.67130 Diameter for "total" magnitude 20032MASX.C.......:20032MASX.C.......:18.5514.47
NOTE: Physical diameters are derived using a scale of 0.0973 kpc/arcsec based on Average NED-D Metric Distance of (20.075 +/- 8.887) Mpc.
The quantities quoted above have not necessarily been corrected for foreground extinction.

View details for 7 Diameter data point(s) available in NED.

Resources for Object NamesSite/Service
Query SIMBAD by primary NED object name -- NGC 3998SIMBAD (CDS, Strasbourg, France)
Revised New General Catalogue -- NGC 3998VizieR Catalog Query (U.S. mirror, CfA/Harvard)
Uppsala General Catalog -- UGC 06946 VizieR Catalog Query (U.S. mirror, CfA/Harvard)
Original Zwicky Catalog -- CGCG 269-025 VizieR Catalog Query (U.S. mirror, CfA/Harvard)
Query UZC Spectral Archive (60 arcsec search radius)Updated Zwicky Catalog Data (Harvard/SAO)
Morphological Catalog of Galaxies -- MCG +09-20-046 VizieR Catalog Query (U.S. mirror, CfA/Harvard)
2MASS Extended Source Images (JHKs) -- 2MASX J11575616+5527128 NASA/IPAC Infrared Science Archive (IRSA)
IRAS Faint Source Catalog -- IRAS F11553+5543 VizieR Catalog Query (U.S. mirror, CfA/Harvard)
Catalogue of Principal Galaxies -- PGC 037642 VizieR Catalog Query (U.S. mirror, CfA/Harvard)
Retrieve mean data from LEDA -- PGC 037642 The Lyon/Meudon Extragalactic Database (LEDA)
NRAO/VLA Sky Survey (NVSS)
GB6 catalog of radio sources -- GB6 J1157+5527 VizieR Catalog Query (U.S. mirror, CfA/Harvard)
Query GALEX (NUV/FUV) Mission Archive (7.2 arcsec search radius) -- NGC 3998GALEX Mission Data Archive at MAST
Explore IRSA resources with RADAR (10 arcsec search radius) -- NGC 3998NASA/IPAC Infrared Science Archive (IRSA)
Resources for position 11h57m56.1s, +55d27m13s (J2000)Site/Service
Query Optical and UV Mission Archives (Default search radius)Multimission Archive at STScI (MAST)
Query High Energy Mission Archives (Default search radius)HEASARC (NASA/GSFC)
SDSS Sky Server
Query IRSA for WISE images (10 arcmin search radius)NASA/IPAC Infrared Science Archive (IRSA)
Band(s): Size:
NASA/IPAC Infrared Science Archive (IRSA)
Band(s): Size:
NASA/IPAC Infrared Science Archive (IRSA)
NASA/IPAC Infrared Science Archive (IRSA)
 Size:    Contours (PS)  JPEG  FITS File 
NRAO/VLA Sky Survey (NVSS)
    Size:     GIF     FITS File  
Faint Images of the Radio Sky at Twenty-Centimeters
The NRAO Data Archive System

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