NGC 3921
NGC 3921 | |
---|---|
![]() NGC 3921, imaged by the Hubble Space Telescope | |
Observation data (J2000 epoch) | |
Constellation | Ursa Major |
Right ascension | 11h 51m 06.863s[1] |
Declination | +55° 04′ 43.38″[1] |
Redshift | 0.019667[2] |
Heliocentric radial velocity | 5896 km/s[2] |
Distance | 277.9 Mly (85.19 Mpc)[3] |
Apparent magnitude (V) | 12.64[4] |
Apparent magnitude (B) | 13.4[4] |
Absolute magnitude (V) | −22.09[5] |
Characteristics | |
Type | (R')SA0/a(s) pec[2] |
Size | 180,200 ly (55,240 pc)[2][note 1] |
Apparent size (V) | 2.1′ × 1.3′ |
Other designations | |
Arp 224, UGC 6823, MGC+09-20-009, PGC 37063 |
NGC 3921 is an interacting galaxy in the northern constellation of Ursa Major. Estimates using redshift put it at about 59 million light years (18 megaparsecs) from Earth.[3] It was discovered on 14 April 1789 by William Herschel,[6] and was described as "pretty faint, small, round" by John Louis Emil Dreyer, the compiler of the New General Catalogue.[7]
NGC 3921 is the remnant of a galaxy merger. The two progenitor galaxies are thought to have been disk galaxies that collided about 700 million years ago.[8] The image shows noticeable star formation and structures like loops, indicative of galaxies interacting.[8] Because of this, NGC 3921 was included in Halton Arp's Atlas of Peculiar Galaxies under the designation Arp 224.[4]
Being a starburst galaxy, NGC 3921 has important features. One of them is an ultraluminous X-ray source, designated X-2, with an X-ray luminosity of 8×1039 erg/s.[9] Additionally, two candidate globular clusters have been detected within NGC 3921.[5] They are both fairly young, and about half as massive as Omega Centauri, demonstrating that mergers of gas-rich galaxies can also create more metal-rich globular clusters.[5]
References
- ^ a b Skrutskie, Michael F.; Cutri, Roc M.; Stiening, Rae; Weinberg, Martin D.; Schneider, Stephen E.; Carpenter, John M.; Beichman, Charles A.; Capps, Richard W.; Chester, Thomas; Elias, Jonathan H.; Huchra, John P.; Liebert, James W.; Lonsdale, Carol J.; Monet, David G.; Price, Stephan; Seitzer, Patrick; Jarrett, Thomas H.; Kirkpatrick, J. Davy; Gizis, John E.; Howard, Elizabeth V.; Evans, Tracey E.; Fowler, John W.; Fullmer, Linda; Hurt, Robert L.; Light, Robert M.; Kopan, Eugene L.; Marsh, Kenneth A.; McCallon, Howard L.; Tam, Robert; Van Dyk, Schuyler D.; Wheelock, Sherry L. (1 February 2006). "The Two Micron All Sky Survey (2MASS)". The Astronomical Journal. 131 (2): 1163–1183. Bibcode:2006AJ....131.1163S. doi:10.1086/498708. ISSN 0004-6256. S2CID 18913331.
- ^ a b c d "NED results for object NGC 3921". National Aeronautics and Space Administration / Infrared Processing and Analysis Center. Retrieved 28 May 2017.
- ^ a b Crook, Aidan C.; Huchra, John P.; Martimbeau, Nathalie; Masters, Karen L.; Jarrett, Tom; Macri, Lucas M. (2007). "Groups of Galaxies in the Two Micron All Sky Redshift Survey". The Astrophysical Journal. 655 (2): 790–813. arXiv:astro-ph/0610732. Bibcode:2007ApJ...655..790C. doi:10.1086/510201. S2CID 11672751.
- ^ a b c "NGC 3921". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 28 May 2017.
- ^ a b c Schweizer, François; Seitzer, Patrick; Brodie, Jean P. (2004). "Keck Spectroscopy of Two Young Globular Clusters in the Merger Remnant NGC 3921". The Astronomical Journal. 128 (1): 202–210. arXiv:astro-ph/0404424. Bibcode:2004AJ....128..202S. doi:10.1086/421851. S2CID 14568163.
- ^ Seligman, Courtney. "New General Catalogue objects: NGC 3900 - 3949". cseligman.com. Retrieved 28 May 2017.
- ^ "Revised NGC Data for NGC 3921 - Hartmut Frommert - SEDS". seds.org. Retrieved 28 May 2017.
- ^ a b "Evolution in slow motion | ESA/Hubble". www.spacetelescope.org. 2015. Retrieved 28 May 2017.
- ^ Jonker, P. G.; Heida, M.; Torres, M. A. P.; Miller-Jones, J. C. A.; Fabian, A. C.; Ratti, E. M.; Miniutti, G.; Walton, D. J.; Roberts, T. P. (2012). "The Nature of the Bright Ulx X-2 in Ngc 3921: Achandraposition Andhstcandidate Counterpart". The Astrophysical Journal. 758 (1): 28. arXiv:1208.4502. Bibcode:2012ApJ...758...28J. doi:10.1088/0004-637X/758/1/28. S2CID 59330131.
Notes
- ^ POSS1 103a-O values used.
External links
Media related to NGC 3921 at Wikimedia Commons
- v
- t
- e
- 3500
- 3501
- 3502
- 3503
- 3504
- 3505
- 3506
- 3507
- 3508
- 3509
- 3510
- 3511
- 3512
- 3513
- 3514
- 3515
- 3516
- 3517
- 3518
- 3519
- 3520
- 3521
- 3522
- 3523
- 3524
- 3525
- 3526
- 3527
- 3528
- 3529
- 3530
- 3531
- 3532
- 3533
- 3534
- 3535
- 3536
- 3537
- 3538
- 3539
- 3540
- 3541
- 3542
- 3543
- 3544
- 3545
- 3546
- 3547
- 3548
- 3549
- 3550
- 3551
- 3552
- 3553
- 3554
- 3555
- 3556
- 3557
- 3558
- 3559
- 3560
- 3561
- 3562
- 3563
- 3564
- 3565
- 3566
- 3567
- 3568
- 3569
- 3570
- 3571
- 3572
- 3573
- 3574
- 3575
- 3576
- 3577
- 3578
- 3579
- 3580
- 3581
- 3582
- 3583
- 3584
- 3585
- 3586
- 3587
- 3588
- 3589
- 3590
- 3591
- 3592
- 3593
- 3594
- 3595
- 3596
- 3597
- 3598
- 3599
- 3600
- 3601
- 3602
- 3603
- 3604
- 3605
- 3606
- 3607
- 3608
- 3609
- 3610
- 3611
- 3612
- 3613
- 3614
- 3615
- 3616
- 3617
- 3618
- 3619
- 3620
- 3621
- 3622
- 3623
- 3624
- 3625
- 3626
- 3627
- 3628
- 3629
- 3630
- 3631
- 3632
- 3633
- 3634
- 3635
- 3636
- 3637
- 3638
- 3639
- 3640
- 3641
- 3642
- 3643
- 3644
- 3645
- 3646
- 3647
- 3648
- 3649
- 3650
- 3651
- 3652
- 3653
- 3654
- 3655
- 3656
- 3657
- 3658
- 3659
- 3660
- 3661
- 3662
- 3663
- 3664
- 3665
- 3666
- 3667
- 3668
- 3669
- 3670
- 3671
- 3672
- 3673
- 3674
- 3675
- 3676
- 3677
- 3678
- 3679
- 3680
- 3681
- 3682
- 3683
- 3684
- 3685
- 3686
- 3687
- 3688
- 3689
- 3690
- 3691
- 3692
- 3693
- 3694
- 3695
- 3696
- 3697
- 3698
- 3699
- 3700
- 3701
- 3702
- 3703
- 3704
- 3705
- 3706
- 3707
- 3708
- 3709
- 3710
- 3711
- 3712
- 3713
- 3714
- 3715
- 3716
- 3717
- 3718
- 3719
- 3720
- 3721
- 3722
- 3723
- 3724
- 3725
- 3726
- 3727
- 3728
- 3729
- 3730
- 3731
- 3732
- 3733
- 3734
- 3735
- 3736
- 3737
- 3738
- 3739
- 3740
- 3741
- 3742
- 3743
- 3744
- 3745
- 3746
- 3747
- 3748
- 3749
- 3750
- 3751
- 3752
- 3753
- 3754
- 3755
- 3756
- 3757
- 3758
- 3759
- 3760
- 3761
- 3762
- 3763
- 3764
- 3765
- 3766
- 3767
- 3768
- 3769
- 3770
- 3771
- 3772
- 3773
- 3774
- 3775
- 3776
- 3777
- 3778
- 3779
- 3780
- 3781
- 3782
- 3783
- 3784
- 3785
- 3786
- 3787
- 3788
- 3789
- 3790
- 3791
- 3792
- 3793
- 3794
- 3795
- 3796
- 3797
- 3798
- 3799
- 3800
- 3801
- 3802
- 3803
- 3804
- 3805
- 3806
- 3807
- 3808
- 3809
- 3810
- 3811
- 3812
- 3813
- 3814
- 3815
- 3816
- 3817
- 3818
- 3819
- 3820
- 3821
- 3822
- 3823
- 3824
- 3825
- 3826
- 3827
- 3828
- 3829
- 3830
- 3831
- 3832
- 3833
- 3834
- 3835
- 3836
- 3837
- 3838
- 3839
- 3840
- 3841
- 3842
- 3843
- 3844
- 3845
- 3846
- 3847
- 3848
- 3849
- 3850
- 3851
- 3852
- 3853
- 3854
- 3855
- 3856
- 3857
- 3858
- 3859
- 3860
- 3861
- 3862
- 3863
- 3864
- 3865
- 3866
- 3867
- 3868
- 3869
- 3870
- 3871
- 3872
- 3873
- 3874
- 3875
- 3876
- 3877
- 3878
- 3879
- 3880
- 3881
- 3882
- 3883
- 3884
- 3885
- 3886
- 3887
- 3888
- 3889
- 3890
- 3891
- 3892
- 3893
- 3894
- 3895
- 3896
- 3897
- 3898
- 3899
- 3900
- 3901
- 3902
- 3903
- 3904
- 3905
- 3906
- 3907
- 3908
- 3909
- 3910
- 3911
- 3912
- 3913
- 3914
- 3915
- 3916
- 3917
- 3918
- 3919
- 3920
- 3921
- 3922
- 3923
- 3924
- 3925
- 3926
- 3927
- 3928
- 3929
- 3930
- 3931
- 3932
- 3933
- 3934
- 3935
- 3936
- 3937
- 3938
- 3939
- 3940
- 3941
- 3942
- 3943
- 3944
- 3945
- 3946
- 3947
- 3948
- 3949
- 3950
- 3951
- 3952
- 3953
- 3954
- 3955
- 3956
- 3957
- 3958
- 3959
- 3960
- 3961
- 3962
- 3963
- 3964
- 3965
- 3966
- 3967
- 3968
- 3969
- 3970
- 3971
- 3972
- 3973
- 3974
- 3975
- 3976
- 3977
- 3978
- 3979
- 3980
- 3981
- 3982
- 3983
- 3984
- 3985
- 3986
- 3987
- 3988
- 3989
- 3990
- 3991
- 3992
- 3993
- 3994
- 3995
- 3996
- 3997
- 3998
- 3999